Or they could go according to storyline. Which is pretty mich behind a time-gated, rep-grind heavy pre-req. Then again they could hand it to us freely. This could be a cash cow scheme for race change service and definitely increased replayability instead of starting with a new race with the quest in their own zones similar to BE/Draenei, Goblin/Worgen, Pandaren.
They could probably introduce a neutral allied race next by about 1 or 2 races and allow you to choose either red or blue or even violet/green.