synchronizing the whole environment with new players would cause huuuge loads of traffic. it probably would lead to lags for people in-game. this is not acceptable. it is not going to happen.
the "auto-join when game is finished" feature of Carnage Contest already is the best possible compromise. you can do other things while waiting because the game will give you an audio signal.
waiting for a game to start will hopefully be less of a problem when the game becomes more stable and better known (=more servers).