Strange choice, if what others have said is still true, expect hotfixing.
I really like the profession bonuses when running the dungeon. It was cool and a fun experience. But in a M+ setting, much like with the covenant bonuses from SL dungeons, I think it should be an "all of them are on" or "all of them are off" situation. It just seems a lot more fair to players. You aren't searching for X profession or resigning yourself to suck it up and make your way through a run you know would be easier if only you could have found X to bring.
Hated that part even when it was current content.Skill should be determining the end results, not such huge RNG.