https://www.polygon.com/2017/11/3/16604468/world-of-warcraft-battle-for-azeroth-allied-races

Allied races are coming to World of Warcraft. In the game’s next expansion, World of Warcraft: Battle for Azeroth, the Nightborne Elves, Highmountain Tauren and Zandalari Trolls will join the Horde, while the Void Elves, Lightforged Draenei and Dark Iron Dwarves will team up with the Alliance.

Unlike Warcraft’s other playable races, these must be unlocked through a quest line. Once players have played through the quests, they will be able to create a completely new character of their newly unlocked race. These new characters begin at level 20 and can be leveled up all the way up to 120.