Originally Posted by
Hitei
Again, it isn't content from the new one.
Allied races, the system, the feature, the ability to bring a group of people into your faction and then play as them. Is the BfA feature. HMT, Void Elves, LF Draenei and Nightborne are four Legion Allied races being introduced with the initial system.
Just like achievements is a system that gives you the ability to measure accomplishments and earn titles and mounts, and some of those are from Wrath, and some are from BC and Vanilla. (read: content from the previous expansion that you have to go back to).
Imagine the confusion of a newbie that boosts to 110 and sees a thundering red cloud serpent. Wow, what's that you say? You have to shrug everything off, stop, go back to MoP and grind mobs for a good week or more?
Imagine the confusion of a newbie that starts up wow with no characters at Wrath launch, and sees DK, wow, but they have to level something to 55, over the course of tens of hours of /palyed time, and then abandon that first character to level a new one to play DK?