Well, this has 2 perspectives. Full geared and low gear. My point is in reatil MOP people can get full honor with alterac valley in ally side. So after 520 gear they get to full random bg and can at least do 70% of class potential and of course play arena.
I beleive the problem is the population itself than dont allow to replicate that alternative system, If a WOD server exist (no idea, because WOD pvp is really sad) even with ashran people will have a hard time emulating the retail progress of gearing.
Add to this that MOP pvp is awesome, but only when you're 550.

