Stacking classes during actual progression happened by far less than in any other expantion. Also, not having the best comp for certain bosses hurt less than in any other expantion meaning bosses like Xhul were actually doable w/o Death Knights (while much harder) unlike Lei Shen on 25.
And that Arcane thingy is the problem comming from:
- the ring
- the fact that content lasts so much and the gear is so good that it goes over certain forseeable scaling issues
Dealing the ghosts on Mythic was something rather new. Finding the balance between people staying out and it. Progressing this boss was a very unique experience - something that never happened before.What new and interesting mechanics did Gorefiend bring exactly....they did the whole 'go into another realm and kill/tank/heal adds thing only last expac on sha, and there have been many other bosses with similar mechanics. The way they made it sound at blizzcon and in Q&As was that the team had a lot of actually new and interesting mechanics which were IMPOSSIBLE to do on two raid sizes....
Also, "having space for more fun mechanics" doesn't mean we will suddenly see a revolution. It means there is space for better ideas tho those ideas still need to emerge. WoD raids felt much different in general than anything before and there is tons of potential for even better stuff.