Sitting out in a tournament/MTT
At GGPoker, if a player is sitting out of a hand (even when all-in) their hand is considered dead. The same would happen in a Live Poker situation and we align ourselves with this school of thought as we believe this is how tournaments should work. If you are not at your seat, your hand is mucked and doesn't remain in play regardless of stack size.
Whilst other sites might have a different policy - we do not model of our policies based on them.