Not really. Because it would be plate and offer 3 specs and not just 1 DOT based dps spec.
But more importantly it’s one of the only magics we don’t have a full class of yet.
We’ve got arcane, fel, death, nature, elements, light. We lack a true void class.
Both DK and Lock have necro spells is a pretty weak argument if you’re gonna say “Paladin and Priest are nothing alike”. They ONLY have holy spells… Literally look at the heal spec of both, it even has the same name. A paladin is a melee priest.
After DH and Evoker, I’d rather they added no more classes.
Counter argument is that honestly most classes could be trimmed down to 2 spec at no real cost, except hybrids, assuming their skill trees become varied and fleshed out enough to preserve all the existing playstyles.
Hunter? Merge Surv and BM.
Rogue? Merge Sin and Sub
Mage? Go back to Arcane spells being utility focused.
Warrior? Can easily merge Arms and Prot if you bring back the stance system.
Same with Ret and Prot Paladin.
On top of my head the only classes where that wouldn’t work would be Warlocks, Monks, Druids and Shamans who would still need at least 3. And even Warlock is debatable as their pets could go back to being more utility focused.
Either way i like that Blizz isn’t too worried about conformity between classes. That would be boring and possibly lead to more design fiascos.
It could be 4-6 years before that happens. When it does, Blizzard will likely be own by Microsoft. It’s hard to say what the future of this game will be by then.
Ignoring all of that, there’s no rule that they have to have perfect measurements for how many classes have each armor type or which hero classes have which armor classes. If that were the case, we wouldn’t have had two of the new classes wear leather, and we wouldn’t have had 3 cloth classes in classic world of warcraft compared to the 2 in every other.
There is only one thing to be sure of when it comes to adding new classes, and that is that it will fit the theme of the expansion and be relatively popular to play (at least for that expansion). Nothing else matters, least of all which kind of armor they wear.
I’d rather they focus on what is missing from the game. Personally I’d prefer another physical ranged class, ideally one that focused on technology, since despite how much WoW focuses on that theme they’ve never had a class for it. But I don’t think it would be a hero class, necessarily.
What I want, of course, doesn’t matter. Blizzard would add whatever they feel fits the game best, and likely the theme of the expansion they are added in.
Their gameplay styles and abilities are totally different. Using the same source of power doesn’t matter.
But if you look at Necromancers a lot of the spells and abilities of Warlocks and DK are what Necromancers traditionally do. Now I do think they could make it work if they copied the Diablo Necromancer or ESO’s Necromancer. Otherwise they’d have to steal a ton of abilities from Warlocks and DKs so what’s the point in even doing it then?
I was wxcited to hear, before release, that the monk would be cloth and do all three. Then it was released with leather…all the games i played monk was best without leather. I beleive LoTrO their ‘bard’ was a clothie. Id go for a bard who can tank in cloth!
But you didn’t offer any suggestions so…
I don’t feel a need for other classes to be added to the game. Same with races, it doesn’t do anything for me.
I’m not opposed to it either.
Neither of those are what a necromancer in Blizzard games has been. Warlocks also control demons and manipulate souls, but they don’t care a lot about raising the undead (in game anyway).
Necromancer would be amazing.
I’ve been thinking that a Lich would be awesome as the next cloth class. It could tank, dps, and heal using shadow and frost magic. For tanking it could use multiple frost shield as its main source of defense, since this will make it unique among the tanks as the first caster tank. The Lich will have the least amount of health of all tanks. Each Frost Shield up to 3 will have its own shield amount which is aroumd 30% of the Lichs max health, and while the shield is active the Lich takes 60% less damage. It will use shadow and frost attacks while using frost to maintain its shields and shadow to heal itself. Because it is a caster tank it can cast more spells at targeted areas, and use spells that can actually explode. The other idea to the Lich is to also summon a few variety of minions to do CC and Leech things for the Lich.
The dps spec will be more straightforward with the powerful cold to destroy and slow enemies movement, and the shadow DoT to kill the enemy while they are slowed.
Healing is done with Shadow spells, and with the Frost spells to slow or stop the enemies movements. I was thinking this spec become a HoT spec with a twist. Like have the spec have 3-4 HoT spells. A quick single target spell that heals little, but makes all their HoT from you heal 30% faster which can stack 2x. An AoE spell that is like a bigger Mind Sear that makes all HoT heal for 10% more over 5 sec. A spell that makes your next HoT be cast on up to 5 other allies within 25 yd of your target. Can cast a Ice Shield thing on an ally for 5 sec that gives them a shield for 50% of their max health, but the ally is unable to move. A big CD could be something with a name like Reapers Gift making the Lich turn into something like a Reaper and for 6 sec all allies within 8 yd can not fall below 1 health, and your healing and critical healing is increased by 30%.
Well jus putting an idea out there. LMK what you think 
I feel like if they were to add Bard it would be either leather or mail. I also think they could actually be another Hunter type that uses ranged weapons and perhaps the other specs could use melee. So like a ranged dps spec, melee dps spec, and a healer spec that can play both.
A new form of priest that uses guns, bows and crossbows like sacred pure energy power like in Inuyasha Kagome and Kikyo forn of battle. Maybe it can be a fourth spec for priest.
My real reply would be too long and branch out to too many things. Ima just say, yes.
Tank spec: cloth class at range that uses pet to tank. Inscribe different runes on the pet for different bonuses.
DPS: bow/gun user with magical ammo
Heal: chemist that uses potions to heal.
Also the first class where each spec gets a profession bonus. Tank gets bonus to inscription, DPS enchanting, Heal alchemy.
Would be nice to have some kind of a buffer class. You would buff others to do more dps or healing or being able to absorb more stuff for tanks.
The portion of which you buff on others count as yours for meters.
An aopthecary sort of like who throws potions at people like Decard Cain in HoTS lol
A wizard class would be awesome to play or a necromancer. Probably doesn’t fit in the lore of the game though.
Shadowpriest’s entire lore is Void-based spells. They may not be healers/tanks, but they are most assuredly void.
That’s a spec not a class though. They also still utilize the light as well as the void, even in shadow specialization.
A void class would be pure void, not anything else.
I’m leaning towards a few things with how past xpacs have been + the direction it could go.
Infinite Weaver
Cloth Healer/DPS
*With the infinite dragonflight coming back into the main scope of the story (Nozdormu/Chromie going to play a big factor in the next content patch for sure, or final one neways)
Voidborn
Cloth Tank/DPS
*My expectations of the Void Lord xpac to be coming soon, so this would tie into that similar to when DH came with Legion xpac
“Generic Cloth Hero list”
Priest, Warlock, Mage spinoffs-
Void Priest
Void Lock
Void Mage
Time Priest
Time Wizard
Primal Wizard
Titan Wizard