Ya but still even in this scenario the 8 teams fighting to be 13 seeds should have to play an extra game while the 14-16 seed doesn't? I don't know that just doesn't seem fair to me. So while in principle its not a bad idea, I still just don't think it could work.
Plus if you think about it the lower conference teams will rarely ever win against the 1 or 2 seeds. A 16 has never won, and a 15 has won what 2 or 3 times? So it would give them a much better chance to win a tourny game, plus it still wouldn't take away their shot at a big boy if they win the play in game. This scenario is of course where the 8 lower conference teams would play to face a 1 seed, which is the best way to do it IMO.