Not trying to troll…
Why are there only Lordaeren humans in the Forsaken? I mean, Sylvanas is an elf, but she didn’t try to raise the other races?
I thought that the plague hit all cities? Shouldn’t there be other races, some of which Sylvanas would have freed?
The plague was specifically designed for humans and entirely stayed within the human kingdoms. Other races could get sick from it, but they wouldn’t die or be raised. So the forsaken were near entirely the former humans of Lordaeron where it struck hardest.
Sylvanas later went grave hunting with her val’kyr, but she kept to humans unaffiliated with the Alliance and the elves who also broke free of the Scourge.
Very much ignorant of the lore, so please bear with me.
What about the trolls in Northrend? I recall there’s a zone of undead trolls.
All good! Happy to help 
Zul’Drak was territory controlled by the Drakkari trolls. They were attacked by the Scourge and in desperation turned on their own loa to get power to fight the undead off. The whole place went a little mad.
Other races can be raised by necromancy, it was just the plague sent to Lordaeron that was human-specific. So some of areas were controlled by Scourge trolls and others were still alive.
But the Drakkari were totally destroyed by the Scourge and us. As a civilization they’re completely gone now save for a handful of scattered survivors out there. The rest are dead or undead.
I really need to wiki walk through the WoW pedia more.
Come to mock? Come to laugh at the speaker for a fallen empire?
Any troll of Zul’Drak not claimed by da Scourge was broken by dem. In there death throws, my people slew our loa, stealing the power of dese gods to wield against the Scourge, and then they died as well.
I be here, now, as little more than a pet for these Zandalari. An oddity dey pull out to show dere children somethin’ exotic.
Leave me be.
-Speaker Malaka’raz
Because only Lordaeren humans were buried in the crypts that Sylvanas used to create the Forsaken.
Game mechanics. Gilnean humans, Scarlet humans, Kul Tirans and high elves are all sizeable minorities amongst the Forsaken.
Realistically they should include all victims of the Scourge prior to vanilla, which includes Blackrock orcs, dwarves, forest trolls and ice trolls.
You should check out Nobbel87 on youtube if you really wanna get into the lore. He has really great videos.
It’s because the Forsaken you play are from Lordareon. They are the OG scourge victims. Similarly how you are a human from Stormwind when you make a human.
However, since Darkspear Trolls are essentially expanding with a few tribe customizations, I guess this could be on the table for Forsaken? However, there is a huge difference from a reuse model vs. skinswap.
Lorewise there are lots of Elf Forsaken too, but they are a minority, not currently playable and they seem to be all Hunters for some reason.
The most prominent one with Sylvanas’ departure is Dark Ranger Velonara.
https://wow.gamepedia.com/Dark_Ranger_Velonara
First generation are freed citizen of lordaeron
Second generation are ressurected by valkyr citizen of lordaeron
Only lich king can ressurect fully functional undead. That’s why valkyrs were needed for Sylvanas.
Just random necromancer can’t ressurect sentient undead that will not die.
Maybe play the game and you will see?
I haven’t been to the Plaguelands in awhile but I believe there are many small troll tribes affected by a kind of undeathly shade to their culture.
As to why there are only human Forsaken it might be because they’re the only type of smarter undead (or likely more numerious undead) to come out of the Northern Eastern kingdoms than any of the other more mindless kind.
Plus there’s the whole influence of the Scourge throwing everything into the mix, and they aren’t likely to part with monstrous creatures if they could avoid it.
There should be a lot of Forsaken Elves in the game as well considering 90 percent of the Thalassian Elves were wiped out and many were raised.
Gameplay really.
But for lore reasons why you only see Human and Elf Forsaken running around, is because that’s where the plague hit. The plagued ravaged Human kingdoms.
Then the scourge that came from it marched toward Quel’thalas, since Humans were really the only guard to Quel’thalas in the event of a land invasion.
So they’re just the most common Undead you’re gonna see.
Technical/Gameplay reasons. Forsaken aren’t just Humans with a different skin tone, like DK’s. They’re their own separate and unique model and skeleton, and doing that for more than one race is far too much work.
Need the forsaken AR to be elves. Preferably NE, since so many died.
I thought it would be neat if they gave us undead versions of the other races as the Forsaken allied race.
I know it will never happen. It would be a lot of work I imagine and probably ruffle too many feathers, but it would have been cool.