Emmm, no. I don't see the idea in Thrall and Vol'jin dying, I absolutely hate the idea of Malkorok being a demon (which is a pretty silly theory in itself,) and Garrosh really needs to go down in this expansion instead of having his story arc being needlessly stretched out just for the same result either way.
If anything, I'd hate that ending.
"I like raiding in WoW, therefore I want the game to end."
My head hurts.