I suppose it depends on the classes getting new specs. If I play those classes, then sure, new specs are great. If I don’t play those classes, then it doesn’t benefit me, so a new class would be better since it might be something I might actually play.
If we’re doing new specs I think it would have to be all or none. You can’t just give 4 classes a new spec every 2 years and expect everyone that’s not those classes to be fine with it.
If we’re specifically talking about the classes and new specs you listed though, sure, why not? I play two of the four classes. One is my main, and the other is a secondary alt.
As for the specs listed themselves, I think they’re fine. A melee mage would be pretty awesome. It reminds me of that one dude from the Witcher tv show. The dude witch who kept fighting and manifesting his own swords. Using magic to augment your physical combat is pretty neat.
DH definitely need a new spec. People have wanted a ranged caster type spec, but I think that would take even more away from the Locks. I think a medium ranged warglaive spec would work though. Maybe using something akin to Kratos’ chaos blades, but with warglaives and fel magic. You could even work in some instant cast spells. It would be another physical ranged class to match the hunter.
Shaman tank… Everyone wants one at this point. (Everyone except the contrarians on the forums) There’s been so much said on this topic that adding to it here is moot.
DK healer isn’t unprecedented. There’s precedence for it in the lore with blood troll magic. Locks also use health funnel, and Blood DK’s literally steal blood from their enemy, enchant it with rune magic and use it to heal themselves. There’s nothing saying they couldn’t use it to heal others. Likewise they could have unholy spells that “Chase off death”, and use frost to offer ice shields/armour.
However, I think a more suitable plate spec would be a ranged holy caster for Pallies. I know priests have been asking for this for a long time now. They want a dps holy caster spec. But honestly, I think both Locks and Mages could use more love in the spec department than priests. There’s so much more you can do with those two classes. And giving it to the Pally is the next best thing. It would be a plate caster and a holy light dps. Win win.
But otherwise, no, we shouldn’t give a small handful of classes a new spec while ignoring the others. You’d also have to wait 3 expansions in order to get another new spec. (Should they continue the trend) Would you want to go 6 years without anything new? I wouldn’t.