Agreed.
Azeroth is very... static. Change that fundamental results in a cascading effect that will make nearly every quest nonsensicle.
So Blizz will
either
A) Regard every new quest with cross faction "freindship" and basically completly ignore every quest pre DF
or
B) Completly ignore it and only pay lipservice in a few sidequest then say "Not this expansion but maybe next" and never do anything about it.