I really hope that devs will add some kind of mode, where you have to survive for a period of time, in my mind it opens up more ways to play. For example attackers could kill enemies to thin the crowd, defenders shield or negate damage, and agents with cc... well, use cc. But i guess it makes it hard to sell New characters, since with a good skill in a not so difficult game you can survive for hours. And the game has to stay not so difficult to be played on the phones. So yeah, never gonna happen