So, all the NPCs that are labeled Necromancers are actually DKs? Kelthu’zad is a DK?
DKs and Necros are what Paladins and Priest are to each other
For real.
While I personally crave cult of the damned necromancy, there is also another canon benevolent necro faction that everybody seems to ignore:
The Auchenai.
Probably will actually be the etherial race for midnight
They have a new model coming.
I’d say half correct. 
Necrolytes were their own thing, outside of both warlocks & Death Knights, so that’s fair.
However
— Warlocks practicing necromancy still came before Death Knights.
https://wowpedia.fandom.com/wiki/Warlock#Second_War
https://wowpedia.fandom.com/wiki/Death_knight#Creations_of_Gul'dan
Thus ~ Warlocks are still ahead of DKs in necromancy … and overall have lore practicing it, so it’s not too far-fetched towards suggesting they get themes as a token nod to such history & lore

final fantasy players
Final Fantasy?!?! What about something actually great like DnD?

So, all the NPCs that are labeled Necromancers are actually DKs? Kelthu’zad is a DK?
DKs and Necros are what Paladins and Priest are to each other
Incorrect. Priests are 50% shadow magic users while Paladins don’t use Shadow magic.
Your comparison only works if you can find a magic school that would encompass half of this Necromancer class, but couldn’t be used by Death Knights.
Good luck.
We have them already.
Why are you guys wanting a minion class so bad?
In my suggested setup for them they’re not really a minion class except for one spec. And even that is only quasi. They have a major tanking pet for the tank spec but most of the rest of the summoning is done as an aesthetic look rather than actual minions. They show up do their ability and then go away again.
The other two specs in my setup don’t use minions/pets in any meaningful way otherwise and focus on the “lich” concepts of shadowfrost and control/support or Stitching and anima magic to steal health from enemies and direct it to allies. (With basic heals when enemies aren’t around that are based around repairing a friendlies wounds.)
Make army of the dead permanent and we have a deal

In my suggested setup for them they’re not really a minion class except for one spec. And even that is only quasi. They have a major tanking pet for the tank spec but most of the rest of the summoning is done as an aesthetic look rather than actual minions. They show up do their ability and then go away again.
The other two specs in my setup don’t use minions/pets in any meaningful way otherwise and focus on the “lich” concepts of shadowfrost and control/support or Stitching and anima magic to steal health from enemies and direct it to allies. (With basic heals when enemies aren’t around that are based around repairing a friendlies wounds.)
So basically Unholy, Frost, and Blood specs……
Why does that sound so familiar?
Sorry that it doesn’t seem to be something you care much for. Other people do though. You’ll be okay.
Ignore Teriz, they’ve nothing to say of value in these topics. They’ve been explained how this would work differently but can’t see anything but “death magic so its just DKs right?”.

Death Knights were created by a warlock.
DKs are 2ND place Necromancers
Wrong Death Knights lol
Yeah thats another thing… Folk seem to forget that we’ve had First gen, second gen, third gen and now fourth gen Death Knights.
They weren’t all made the same way or have the same results… (Though mostly the same thing for Second through fourth.)
Ner’zhul just called his Second Gen Death Knights cause he liked the concept. They’re not the same as the First Gen really…
Warlocks still did high-tier necromancy before the later variation of Death Knights did.
Point still stands.