While you did do yourself a disservice by not taking an acceptance off of the waitlist and it was a very short sighted decision, you don’t need to worry about the potential of getting blacklisted. When you have a previous acceptance, AAMC does record that information for internal use and to report back to your undergraduate advisor if you gave them that permission, however that information is not communicated to medical schools and will not show up on future reapplications.

Every school in which you were waitlisted at will already know that you have been waitlisted at a certain number of institutions and if you did get an acceptance they would know about that as well. Also some schools do in fact ask about it on their secondary but these are few and far between. Outside of these few institutions, your application would basically be a fresh start.

Schools don’t talk to one-another. They get 10,000+ applications a year and have several hundred interviewees a year. They don’t have the time nor do they care enough to communicate about individual applicants by name or number, and this would be in direct conflict with the AAMC’s policies on applicant privacy.

Don’t worry about it, you will be fine. Just take a deep breath, internally reconcile your mistake, and move on.