oops - meant to quote Texaschick123 re: contract having existing reservation.
Here's the deal, unless your offer had a cannot close before Jan. 2018 clause(which is how existing reservations are usually handled,) the deal could close as per the contract terms & that reservation would be automatically canceled when title changed & sellers kids (or renters) would be out of luck, the points would be yours. Your broker should have advised you of this.
In fact I remember a thread a few years ago with a cannot close before clause that
DVC ROFR'ed and closed too early automatically canceling the reservation creating chaos for the poor point renter (who'd also been the attempted buyer of the points ROFR'ed.)
Nevertheless, sounds like a super flaky situation and best to cut bait, IMO.