I'm thinking yes, they should... I feel like, how manageable a game's size is or isn't has less to do with the number of characters and a lot more to do with the number of players, so if a player isn't feeling a character and wants to drop, but doesn't necessarily want to leave the game, I think it's fair to give them the chance to app someone else in.

I think it could also have some interesting IC implications if the Ingress started spitting people out at more random intervals like that, lol