When I saw Violet Hold returning, I thought "Oh, that's okay, the place can return but they won't do the same mechanic again, that'd be silly."
Oh.
Edit: And during the Legion reveal, it was stated that "Violet Hold had some deep secrets that we didn't discover the first time around, but these are now awakened by proximity to the Tomb of Sargeras. We learn more about the origins of Dalaran, mages of Dalaran, and the origins of the world itself."
Uh huh.
Come on now, it's the best dungeon since Maraduon.