Hmm... I dont think this will happen. At least I dont see it.
The closer that gets to it, at the moment, its Nova Uni
Nova Uniao could get three weight classes if Barao or Aldo could hold two belts.
AKA is another possibility, with Rockhold, Cormier and Cain. I'm sure they've got some decent WW's too right?
I doubt there'd ever be a camp that will have champions in every weight class.