Absolutely no new island will open up while all the existing ones are having issues of low player population.
500? That would bring us back to old levels. Get me 1000 new players and I'll make a new continent.
What if every player in the game had to play on the new island with one character? How many players would that be?
Bring back a war island, and pack 1200 characters on it!
Cool! The war islands were nice and small, or, nice and cozy for everyone to mash on!