The fact is, Death Knights should have had access to a majority of the allied races introduced.
Dark Iron - they weren’t part of Horde or Alliance, but they weren’t complete recluses. They were abundant in the Searing Gorge and Burning Steppes - the later of which had necropoli over it during the cannon Scourge invasions that preceeded Naxxaramas and Wrath. It doesn’t make sense that the Lich King would ignore them, especially considering that they are considered a hearty breed of the Dwarves.
Kul Tiran - a well traveled and naval nation prior to them receeding from the Alliance. They certainly would have had some peoples scattered throughout the Eastern Kingdoms who didn’t pack up and leave just because Daelin Proudmoore died. If a few escaped Sons of Arugal can be justified for Worgen, then so can Kul Tirans.
Void Elves - these are just Blood Elves that decided to follow Umbric and his ideology of protecting Silvermoon. There is nothing, and I mean nothing, stopping a Death Knight from following this ideology just like every other class. In fact, the “at any cost” mentality of Umbric isn’t an unfamiliar one to Death Knights in general, with recent examples such as accepting the hatred and blame of the world had we succeeded in raising Tirion as one of the Horsemen in the name of protecting Azeroth from the Legion.
Zandalari - present not only in the Eastern Kingdoms, but also in Northrend alongside the Drakkari. They specifically went to Zul’drak to aid their brothers against the Scourge, and then with Drakuru’s betrayal it’s almost impossible to imagine that no Zandalari were risen. This is possibly the most eggregious omission.
The races that don’t work: Lightforged Draenei, Mag’har Orcs, Nightborne, and Highmountain Tauren. The Lightforged and Mag’har weren’t on Azeroth until very recently, and the Nightborne and Highmountain tribe were secluded enough that they never had any interaction with the Scourge. While Trag Highmoutain is a canon character, he is an excepion with highly uniqe circumstances that led to him becoming a Death Knight, and one free from the Lich King’s will at that - he is not an applicable case for the entire race. We would need to see a new wave of Death Knights being raised for any of these races to be considered for the class.
Edit: I completely forgot to include the Nightborne in the original post. I have now added them in appropriately.
Fun fact, it’s stated when you make a Worgen DK and do the starting experience that you’re NOT Gilnean. You’re from a different tribe of Worgen altogether, specifically the Bloodfangs from Silverpine:
From the quest A Special Surprise, when you do it as a Worgen:
Lord Harford says: Come to finish the job, have you?
Lord Harford says: You’ll look me in the eyes when…
Lord Harford says: <Name>?
Lord Harford says: <Name>, I’d recognize that face anywhere… What… What have they done to you, <name>?
Lord Harford says: You don’t remember me? We were both servants of Arugal back in Silverpine Forest. We put up with his merciless torture for ages. It was you who saved me on that fateful night when we escaped Shadowfang Keep.
Lord Harford says: Without you I would have died. YOU! The most noble worgen I ever knew.
Lord Harford says: What have they done to you, <name>? How could this have happened?
Lord Harford says: Remember the worgen you once were, <brother/sister>! You were our savior! Fight this!
Lord Harford says: Listen to me, <name>. You must fight against the Lich King’s control. He is a monster that wants to see this world - our world - in ruin. Don’t let him use you to accomplish his goals. You were once a hero and you can be again. Fight, damn you! Fight his control!
Knight Commander Plaguefist yells: What’s going on in there? What’s taking so long, <name>?
Lord Harford says: There… There’s no more time for me. I’m done for. Finish me off, <name>. Do it or they’ll kill us both. <Name>… Remember Gilneas, our beloved home. This world is worth saving.
Lord Harford says: Do it, <name>! Put me out of my misery!
It’s the same thing for Goblin DKs. You’re not a Bilgewater Goblin like other PC Goblins, you’re from the Steamweedle Cartel.
… who were Gilneans. Read Arugal’s lore. It tells you that after the Nelf Worgen killed the Scourge, they turned on the Gilnean soldiers. And those Gilnean Worgen went after Baron Silverlain’s keep. Arugal felt guilty, adopted them, it became Shadowfang Keep.
I think more important than letting Allies be DKs is letting only DKs choose faction regardless of race. I don’t see why an undead human DK couldn’t side with Sylvanas.
AU Maghar orcs wernt there either. Neither were the nightborne because they were isolated. Scourge wasnt on the broken isles as far as we can tell. There’s a lot of nono’s in terms of DK’s
I will grant I forgot about the AR orcs. My bad on that.
NIghtborne was there though. Eilsande has sent dissdent elves outside the bubble for years. Some could even leave of own free will.
Now why would an exile head to northrend…who knows. It could be as simple as it seemed like a good idea. They met Arthus…got turned.
Getting in DH RP I can’t judge “a good idea” motivation. Both races char’s backstory is they thought being a fel infused emo psychotic elf was a good idea lol.
Also I will fall back to the level 20 start. All allied races exist to be made DK’s. Same as core races. we may just be the one but…that is how the game works. As seen in legion with DH’s. Story/lore wise we were just the one DH leader for our story. Otherwise legion would be a real quick expac to play.
Hey, all 1000 of you DH’s. You run 1000 armies, have 1000 fel hammers. Go here, focus fire and this demon war is over.