That they take time to set up their expansion features and follow through, no half assed stuff anymore.
Do some more reiterating at spec base-kits (i.e. fire was one of the best m+ specs but the actual aoe filler rotation is a 3.5 second targeted hard cast, what the f*ck)
-The raid and m+ is like always top notch but things like obviously half baked domination sockets/shards hurt.
-Bring back tier sets with 9.2 and never EVER get rid of them again.
-Less obnoxious player power grinds outside of gear, i bet players would have been a lot nicer to torghast if it wasn't mandatory for weeks on end on every character you wanted to play....