I am not sure why does it matter if it's in the game or not? Are we playing legion now? I mean it's already in the game
As for tier sets, switching that around isn't hard, unless you think we will go till early 2017 without tier sets?
- - - Updated - - -
Are you even reading? They want to put a small raid BETWEEN the raid tiers. NOT between the raids.
Meaning, these are two separate raid tiers.