FWIW I accepted offers, and then declined them when I received an offer from another school that was higher on my list. I also continued to receive interview offers after accepting. For example, I heard back in early October from TWU. I accepted, went to visit them and then decided to accept UNT instead. I did respond with a nice email to Mary Beth, thanking her for everything and letting her know I would be attending a different program. She responded by thanking me for letting them know. That was it. I then had other schools offer interviews and acceptances and I ultimately went somewhere else besides UNT. I did get an acceptance offer from UTHSCSA also, so it obviously wasn't an issue for them that I had accepted elsewhere. I think that schools can't expect you make a final decision this early in the process and they do expect changes. That's why they offer extensive wait lists. Perhaps in March or April, they may double check further to make sure no one is holding two spots. I don't know. Just sharing my experience and how I handled it. As long as different schools have different time frames, it is to be expected. My top choice school didn't let me know until December, but I wasn't going to not accept at UNT and let that go. Hope that helps. YMMV.
