I suspect it was to comply with (ridiculous) censorship in China. It's a bit annoying because I really liked my golden Headcrack and Bite, but now their animations are mediocre at best.
Not to say all your views are wrong (too much of this is subjective) but it is worth viewing everything from the other side, which is my intent as I pose counter arguments.
Draw in shaman: your sentence could exchange 'shaman' -> 'rogue' and 'card draw' -> (most of rogue's weaknesses) and make something people have asked for years. In short the answer is: probably yes. You are free to make traditional control decks for these classes, in the same sense as control warrior or priest, but of course they won't be as good. Instead you modify them to fit the tools available until you might not even call them control decks anymore.
Quite frankly: good. The whole point in having 9 classes is to limit tools available to any given deck. Every class should end up better than everyone else at something, to the point where other classes trying to mimic them are liable to be weaker and be considered 'not viable'. They might be OK in the grand scheme of things (e.g. control shaman > control rogue, hunter and druid), but being middle strength means nothing for the meta.
Anyhow, how does this respond to your question? It says if you want to make a control deck and card draw is important for you, you weigh up the options and discount shaman. Which I believe is much better than having the situation where you look at all 9 classes and all are equally good at everything.
Draw in hunter: firstly, draw came under 'limitations' (not a nicely defined thing in my book) rather than 'weakness', so by they made no suggestion of never printing conditional card draw again. Just that it will happen rarely. Even if they chose not to, I would be OK with it. As with shaman above, I think it is good to have the capacity to draw cards factor into decisions on which class to choose for a given archetype.
Priest only has Inner Fire: cf Nomi, Mecha'Thun, and others exist. A lot of decks do use Inner Fire because if the plan is for things to ever stick anyway, then it is an easy and cheesy win. E.g. silence priest doesn't have to run Divine Spirit + Inner Fire, but it lines up with the plan since it wins with minions punching the face anyway. In this case I would argue big, cheap, silenced minions are the primary win condition, with DS+IF as a powerful alternative in case the situation arises where it does the job.
Demons as a 'strength': if neutral demons didn't exist I would agree with you. However, they do and there is no denying warlock generally has a much greater capacity to exploit them than other classes do, just because they have the demon tribe.
As for whether demons (and totems, and every other tribe since none are made use of equally well by all classes) should be listed as weaknesses of other classes: sure, if you want the full list they'd be there. But does this really need writing down?
Warriors not caring about going wide: well, it's never part of their game plan because warriors suck at it. If they were good at going wide you can be sure they would do it sometimes. View it this way: you want to make a deck that goes wide, but are yet to even pick a class. Among others you discount warrior because it has nothing to make the deck work, and instead land on druid, shaman, warlock or pally (possibly hunter if you are a fan of the class). Why? Because the chosen archetype plays to their strengths, while the other classes are weak at it.
Same goes for armour in mage. Its not part of the game plan precisely because they are weak at it. If you try to instead argue mage just happens to not include it in their game plan through choice, then be my guest and make an effective armour-focused mage....
The rule of thumb is: if a mechanic is never part of a class' game plan, its probably because they are weak at it.
Druid/rogue auto-lose to a tall and wide board: well yes, they can struggle to deal with it effectively. But that doesn't mean they cannot beat decks that build such boards; they just have to prevent the board being built in the first place. E.g. rogue can single target kill minions as they come down before they build up. Yet again this is good as it means each class plays differently.
Re turn 4 Mountain Giant in mage: turn 4 Mountain Giants are nothing new (see Handlock), and that is something I don't mind. How they multiply if you cannot deal with them is however a problem and I agree it is much too punishing just for a choice of class. Mana cheating and giants have caused so much grief over HS's history that I have to wonder whether they should change a minion's mana cost to its played cost rather than base one...
I imagine they produced it because when Mike Donais suggested Mind Blast was being considered for the Hall of Fame a while back, on the basis of it conflicting with class identity, there was a bit of an outcry largely revolving around how poorly defined many people felt class identities were. I wrote a big long forum post about in on HearthPwn at the time, some of which is a little outdated (because it was pre-RoS and healing in druid looked to have been replaced by armour gain), but for the most part it lines up with what Blizzard wrote.
Anyway, this looks like yet another response to what the community asked for, so good job Blizz again.
Vanish is mass AoE (kind of) in rogue, and stands as a good example of where basic and classic cards are no longer in line with class design. I made a thread about evolving class identity on HearthPwn a while back and flagged Vanish as a card that could justifiably be targeted. (In fact that thread was a response to disbelief about Mike Donais suggesting Mind Blast moving, which is fitting.)
Poisonous however is still very much in rogue, albeit a part that has long been under-/un-used, and replacements to HoF cards do seem to be about re-aligning the evergreen sets with current class identity.
Well radiance is reverse mind blast, so you can meme even harder by OTK-ing yourself with a little help from an Auchenai?? The real beauty of the deck is that you then climb the ladder in reverse too! Its so thematic.
I suspect it was to comply with (ridiculous) censorship in China. It's a bit annoying because I really liked my golden Headcrack and Bite, but now their animations are mediocre at best.
Not to say all your views are wrong (too much of this is subjective) but it is worth viewing everything from the other side, which is my intent as I pose counter arguments.
Draw in shaman: your sentence could exchange 'shaman' -> 'rogue' and 'card draw' -> (most of rogue's weaknesses) and make something people have asked for years. In short the answer is: probably yes. You are free to make traditional control decks for these classes, in the same sense as control warrior or priest, but of course they won't be as good. Instead you modify them to fit the tools available until you might not even call them control decks anymore.
Quite frankly: good. The whole point in having 9 classes is to limit tools available to any given deck. Every class should end up better than everyone else at something, to the point where other classes trying to mimic them are liable to be weaker and be considered 'not viable'. They might be OK in the grand scheme of things (e.g. control shaman > control rogue, hunter and druid), but being middle strength means nothing for the meta.
Anyhow, how does this respond to your question? It says if you want to make a control deck and card draw is important for you, you weigh up the options and discount shaman. Which I believe is much better than having the situation where you look at all 9 classes and all are equally good at everything.
Draw in hunter: firstly, draw came under 'limitations' (not a nicely defined thing in my book) rather than 'weakness', so by they made no suggestion of never printing conditional card draw again. Just that it will happen rarely. Even if they chose not to, I would be OK with it. As with shaman above, I think it is good to have the capacity to draw cards factor into decisions on which class to choose for a given archetype.
Priest only has Inner Fire: cf Nomi, Mecha'Thun, and others exist. A lot of decks do use Inner Fire because if the plan is for things to ever stick anyway, then it is an easy and cheesy win. E.g. silence priest doesn't have to run Divine Spirit + Inner Fire, but it lines up with the plan since it wins with minions punching the face anyway. In this case I would argue big, cheap, silenced minions are the primary win condition, with DS+IF as a powerful alternative in case the situation arises where it does the job.
Demons as a 'strength': if neutral demons didn't exist I would agree with you. However, they do and there is no denying warlock generally has a much greater capacity to exploit them than other classes do, just because they have the demon tribe.
As for whether demons (and totems, and every other tribe since none are made use of equally well by all classes) should be listed as weaknesses of other classes: sure, if you want the full list they'd be there. But does this really need writing down?
Warriors not caring about going wide: well, it's never part of their game plan because warriors suck at it. If they were good at going wide you can be sure they would do it sometimes. View it this way: you want to make a deck that goes wide, but are yet to even pick a class. Among others you discount warrior because it has nothing to make the deck work, and instead land on druid, shaman, warlock or pally (possibly hunter if you are a fan of the class). Why? Because the chosen archetype plays to their strengths, while the other classes are weak at it.
Same goes for armour in mage. Its not part of the game plan precisely because they are weak at it. If you try to instead argue mage just happens to not include it in their game plan through choice, then be my guest and make an effective armour-focused mage....
The rule of thumb is: if a mechanic is never part of a class' game plan, its probably because they are weak at it.
Druid/rogue auto-lose to a tall and wide board: well yes, they can struggle to deal with it effectively. But that doesn't mean they cannot beat decks that build such boards; they just have to prevent the board being built in the first place. E.g. rogue can single target kill minions as they come down before they build up. Yet again this is good as it means each class plays differently.
Re turn 4 Mountain Giant in mage: turn 4 Mountain Giants are nothing new (see Handlock), and that is something I don't mind. How they multiply if you cannot deal with them is however a problem and I agree it is much too punishing just for a choice of class. Mana cheating and giants have caused so much grief over HS's history that I have to wonder whether they should change a minion's mana cost to its played cost rather than base one...
I imagine they produced it because when Mike Donais suggested Mind Blast was being considered for the Hall of Fame a while back, on the basis of it conflicting with class identity, there was a bit of an outcry largely revolving around how poorly defined many people felt class identities were. I wrote a big long forum post about in on HearthPwn at the time, some of which is a little outdated (because it was pre-RoS and healing in druid looked to have been replaced by armour gain), but for the most part it lines up with what Blizzard wrote.
Anyway, this looks like yet another response to what the community asked for, so good job Blizz again.
Vanish is mass AoE (kind of) in rogue, and stands as a good example of where basic and classic cards are no longer in line with class design. I made a thread about evolving class identity on HearthPwn a while back and flagged Vanish as a card that could justifiably be targeted. (In fact that thread was a response to disbelief about Mike Donais suggesting Mind Blast moving, which is fitting.)
Poisonous however is still very much in rogue, albeit a part that has long been under-/un-used, and replacements to HoF cards do seem to be about re-aligning the evergreen sets with current class identity.
Well radiance is reverse mind blast, so you can meme even harder by OTK-ing yourself with a little help from an Auchenai?? The real beauty of the deck is that you then climb the ladder in reverse too! Its so thematic.