Might mean nothing, but in the Achievement and String changes on the new PTR Build 25600 there are these named:
World Safe Locations
A Dark Place
7.3.5 - Uuna Scenario (New)
Forge of Aeons
7.3.5 Lightforged Draenei - Unlock Scenario - Start (New)
Forge of Aeons (New)
So I'm still going with the theory that they will be part of 7.3.5 although maybe not right when the patch hits the servers.
Edit.: Also, would it make sense for 7.3.5 to hit servers and have all our racial leaders stand in the embassy talking about how we should recruit those 4 races to join our alliances for months?