Many of the threads about PvP here have the common theme that PvP development for DCUO is unprofitable. So make it profitable by closing off some arenas for only members and adding a new season for new 102 gear or even higher 110 gear. Then plan for a 50 v 50 new arena or instance as the next stage. When the gameplay stats show the utilization warrants attention from the development team then PvP will get some fixes from them.
While your idea sounds interesting, I honestly don't think the PS4 could handle a 50 vs 50 battle with animations, unless they make/use a huge map.
We can do 50 vs 50 now in open world PVP. All you need to do is form groups and do it. People constantly talk about PVP being dead and yet they do nothing but sit on their backsides and wait for someone else to do something. Watching these dude talk trash about PVP being dead all the while sitting, twiddling there thumbs and doing nothing makes me LMAO. It gives me flash backs about going clubbin in the old days. Seeing all these dudes all dressed up & sitting on the side of the dance floor while I'm out there with all the ladies dancing. xD Quit being nervous and get your butt out there and do something.
Members Only PvP is a terrible idea. When the Last Laugh DLC launched, it had exclusive PvP maps that were only for members/DLC purchasers. The end result? They never, ever popped. We couldn't get into those Arenas, because the queues were already almost empty, so the non-exclusive maps would pop first every time because you actually needed the FTP guys just to get enough numbers for anything to pop. In the end, SOE acknowledged it was a terrible idea and opened those maps for everyone, which then made the Last Laugh DLC have almost no real content for purchasing it. They basically had to give a DLC away for free, just because the people who bought it couldn't use it due to a Members Only/Purchasers Only restriction. PvP has not increased in popularity since that time, and the queues are definitely not popping faster. If anything, it's got worse. So making a Members Only PvP map would have the same or worse results.
I have seen more than 200 toons in the WT attacking a Mepps BAM (big a** monster). And a members only new arena with new gear and a shiney mat or aura that was PvP only available after you complete gear set 102 (or 110) would attract people to this game mode and provide a visible reward/goal. 50v50 in an arena is unrealistic for que time, but an open world area with a BAM or two to fight/help is not that different than Ring War with sub-Avatars. Oh and when I went premium the first time, I bought Last Laugh among other DLCs, right when rage came out and had no problems leveling up to max 100 (at the time 100 was max) on a new rage toon. One of the reasons ques don't pop is because people are maxxed out on cr level and feats. Just adding new feats and cr will increase arena pvp play, imo. Also open world PvP, say Ring War with sub-Avatars, helps hide the imbalances in powersets with shear numbers and having a goal to accomplish in the instance.
PvP is low population, because not many people want to play it atm. Same thing goes for PvE and whole game actually.