I’ve got two for each faction.
Alliance:
Murlocs
Possible Classes: Warrior, Hunter, Priest, Shaman, Demon Hunter, Death Knight and Warlock
Explanation: Murlocs are THE most recognizable race in the Warcraft universe. Its honestly baffling how they aren’t playable already. While aesthetically, they fit in better with the Horde, they would fit better with the Alliance lore-wise due to the fact that there already IS a Murloc NPC on the alliance.
Vrykul
Possible Classes: Hunter, Mage, Shaman, Warlock, Warrior, Death Knight and Druid
Explanation: This one is pretty much self explanatory. All humans descended from the Vrykul so naturally, they’d be part of the Alliance. The only reason we don’t have Ogres is because they’d be too big to fit through doors. However, the Vrykul canonically have runic magic at their disposal which also canonically can shrink things. Because of this, it is the only giant race we can have without any of the issues that would come from being giant. Just compress them to a smaller size when they go indoors as one of their racials and boom, problem solved and its still lore friendly. So since this is the only giant race we could possibly have… let’s… have it.
Horde:
Sporelings
Possible Classes: Warrior, Paladin, Druid, Mage, Rogue, Hunter and Monk
Explanation: Barely anything is known about he Sporelings. In fact, most casuals don’t even know they exist. Which makes them perfect to add as a new race because they’re an established people already in the lore while being able to feel “brand new” to a lot of people. Also, they have a capital city. I originally thought they’d fit in better with the Alliance since they would compliment the Draenei aesthetic quite nicely but they DO have a tribal and primitive aesthetic that would also work jsut as well if not better for the Horde.
Dreadlords
Possible Classes: Warlock, Rogue, Mage, Death Knight, Demon Hunter and Druid
Explanation: Okay hear me out. I know tons of people who would like to play as a demon and Dreadlords are the most “civilized” type of demon so if any of them would be playable, it’d be them. Horde because Alliance don’t even like having Warlocks, Death Knights or Demon Hunters in their ranks. I’m pretty sure literal demons would be crossing the line. And hey, Orcs already have demon blood in them so… Its not like that ever stopped them before.
And as a bonus for if they would ever add any more neutral races to the game like the Pandaren, I’ve prepared two for that too. (And let’s be honest, none of us would be surprised if they just removed factions entirely next expansion anyway):
Arakkoa
Playable Classes: Rogue, Hunter, Priest, Druid, Shaman, Monk and Mage
Explanation: Life is a curse. Simply… cawful.
Faerie
Possible Classes: Paladin, Hunter, Priest, Shaman, Mage, Druid and Warlock
Explanation: Because we have no actual cute race. Everything else that is meant to be a cute race (Gnomes, Goblins, Pandaren and Vulpera) are actually kind of horrifying. But these guys are ACTUALLY adorable