I think, overall, if they bring back level scaling, this patch will be better than WoD.
The removal of enchants is a good thing. ("Better," for me, means more balanced, skill-based competitive play.)
Disc priest is still way better than every other class, but that was the same in WoD; it's a problem, but not a new one.
There are a lot of pros and a few cons, (outside of the lack of level scaling, which IS a bracket killer IF they don't fix that, BUT they probably will.)
But the main problem in WoD was competing with 29s, certain 29 classes: the 29 BM's Guard ability and the 29 Warrior with Crusader buff. Also the wind walker stun was overpowered. ALL of those problems have been ameliorated. BMs lost Guard, if I'm not mistaken. WW lost the full to zero health stun. Warriors lost crusader in pvp. But the WW and War are still both very viable strong classes.
If they bring back level scaling, I predict 20s will be far more competitive with 29s in both arena and bgs than they were in WoD. The 20 and 29 ladders will be more mixed, and everybody will have more fun.
If your current or favorite class feels less competitive, it may be time to branch out and try other classes. New meta. I have mained 6 different classes for long periods of time since F2P WoW was introduced, and they were all fun.
Of course there are, and will be, balance issues and bugs. Some classes will not be competitive. Everybody will end up playing 4-5 classes, same as before, just different ones. But that's always been the case.
A reminder: When WoD first came out, they introduced level scaling in bgs, but it did NOT work in arenas for a month or more, till they got around to implementing scaling in arenas too.
With this patch, they didn't mention anything about removing level scaling; if it were intentional, they would have mentioned it. We are currently in the expansion "pre-patch." I recommend giving them at least until the expansion itself goes live, or a month after that, to fix level scaling before abandoning the bracket completely.