AAMC says you must decide by may 15 whether or not you will matriculate at a school. So if someone decided to matriculate in school A, and submitted the decision to that school, and somehow school B's waitlist started moving (on May 16th) and that person is the first on the list, will that person be able to matriculate at school B? first of all, will school B even contact that person since he has already submitted the LOI.