...honestly - I think the way you do. That players could test the waters, so to speak, and then return to their same team.
But in the discussion they were saying that once a player has entered the portal, they are essentially off the team. They are in no-man's land and really can't return. I honestly don't remember the details other than to recall that it seemed pretty intense and I was surprised at they way they described it as all ties to the team being severed and a return really isn't an option.