Some wish for Turalyon to go mad, or for Alleria, something I deeply disagree with since turning characters into villains just for the sake of having antagonists and without valid explanation or good storyline to go with is one of WOW's oldest, most recurrent and worst story tools and that it didn't make the story of the Burning Crusade better with Illidan and Kael'thas, nor with the Horde during MOP and BFA with Garrosh and Sylvanas.
It would just make the story again worse that it already is.