What does any of this have to do with why arena caps exist?
HiTech
As far as I know arena caps exist because new players were not becoming subscribers, the MA contained to many players. That when the arena cap system was implemented the new players started signing up in droves and older long time players stopped leaving the game. Or at least that's the word that Skuzzy put out.
If that is the reason, perhaps you could have the two LWA arenas with the current cap system and that would be the only LWA that non subscribers could access, that way they are forced to play in a safe, controlled, fun environment. Just add one more LWA with no cap environment so that the squads could get in and the old timer would have an arena with no caps, None subscribers would not have access to this unsafe, uncontrolled, environment.