best I could think of to make this "viable" is as a catch up mechanic to be honest, for example when 4.0 comes out make the "MSQ" dungeons open world, so instead of queuing up to clear you can run into the zone and kill the NM last boss/ get item there. (as an extra option along with still just queuing up or platoons (assuming i am understanding how they work and a newer player could even access em that early on)) Still even this i don't see happening and I think were underestimating the amount of work to actually making it "open world", after all it would be work for the world design team, on top of making more world for the then current/future areas of the game.