Ok, at the risk of getting shouted at by PVPers, narratively PVP has been shoehorned into the game and literally has no reason to exist content-wise other than people like and want PVP. And that's absolutely cool. So just double the maps and let Bloody Bay, Warburg, Siren's Call, and even RV if need be have PVE iterations as well. And why not PVP versions of Echo DA and the Rikti Crash Site?
"But the content is getting the Shards and getting the nukes." Yep. And what has that actually got to do with PVP? Literally Nothing. ONLY RV has any smidgen of a reason for PVP narratively.
Ideally I'd like to see the south islands developed into something, as @TemporalVileTerrormentioned above, but I'm back to leveraging assets that already exist. Doubling a map isn't hard, the game itself does it for numbers caps. Now do it manually and change the flags for PVE/PVP.
Of course all this, if it were ever to happen, is sitting in a queue behind KW getting fixed.