The big thing I am always waiting for with these sims, is an ongoing online persistent theater of war, where anyone can join/leave and complete missions across the frontline, with AI planes doing their job too.
Something like the good old Falcon4 thing, but in MMO style like Elite Dangerous.
Honestly, I don't know if its technically feasible or not, most probably you need a bunch of servers and separate areas into instances which you can move between seamlessly.
But hey, dreaming is not prohibited, right?
