I can say it is somewhat common to observe a game (or two) while waiting in a staging window or the lobby for a game of your own to start.
@RoiEX it would be good to know a couple things as well specifically regarding the updated behavior:
A) would the lobby window closes when connecting to a game? Currently it does not, would this change?
B ) assuming the lobby window stays open, what would happen if a user did try to connect to a second game
We can maybe pull stats from DB for how often a player connects to multiple games, I don't think it is rare per-say. It is a question though whether the "hassle" to fire up another TripleA instance manually, login to lobby again, all to join a second or a third game would be a major annoyance.