Should BfA's release date be delayed if classes are not in a respectable state by September? Legion's classes were rushed out of the gate and most classes never recovered as the expansion went on. In fact, some got worse.
I'd rather wait another few months and have BfA released at the end of the year or the start of next year to maximise the probability of classes being respectable. Because with a September release that seems unlikely. And there's little hope of the classes being fixed throughout BfA.