My impression is that the school is trying to fill all their slots and since they have already given out all their financial aid, they are waiting to see who turns them down so that any financial aid they received can go back into the pot to be redistributed to those who are waiting on their package before they make their decision. IMO, the reason for the May 1st deadline is so that the schools have a more even playing field. This way schools can’t undercut or start a bidding war for students. To me, this is a red flag. If they are this way handling this, what are they like about everything else.