So, are you saying that schools with limited funds (presumably mid tier and lower schools) tie up money in their top candidates, and then, when the top candidates have better offers and withdraw, they redistribute to those left after the PTE deadline (people who didn't have better offers, or no other offers at all) and those on the WL. If so, that kind of seems like a backwards way of distributing limited funds, since they fail to yield the top candidates, who already have better offers elsewhere, and then lose the middle candidates who would have happily accepted the money had it been offered prior to the deadline, but who go elsewhere since there was no money for them, only to give the money to those who have no better offers on or after 4/30, who presumably are the accepted candidates who they actually want the least!
Is that really how it works? The more I learn about this process, the less sense it makes to me, but also the less anything surprises me!! 🙂