My newest theory about TWW and into Midnight:
Alleria and Thrall were the bosses of the Visions of N'Zoth, Anduin was (request by blizzard to the Author of the book) in the post BfA book showing dark magic on his hands.
All three of them are the faces of TWW? and the expansion after wards is full on void focus? No coincidence. All three of them might fall to the void and Xal'atath might win the war within these characters, even if we beat the bosses in the expansion.