CalebHughes yes, it has happened and it is bad when it does. There have been real cases where Caribbean schools lost ECFMG eligibility while students were mid-program. What that means in practice is that students suddenly can’t register for the USMLE, federal loan disbursements can stop, and the hospital affiliations for clinical rotations can fall apart. The accrediting bodies will usually give a school some runway to wind down and sometimes help students find transfer options at other programs but there is no guarantee of a smooth landing. It is one of the strongest reasons to go with a school that has been accredited for a long time rather than one that just got it last year.
Something nobody has brought up yet and it is a big one for Canadian students in particular. A lot of Canadians end up in Caribbean schools and just assume the accreditation stuff being discussed here applies to them in the same way. It partly does since ECFMG certification is still needed if you want to do residency in the US. But if your actual goal is to come back to Canada after training, the Medical Council of Canada has its own requirements and the IMG pathway into Canadian residency is honestly much harder than the US pathway. The spots for International Medical Graduates in Canada are very limited nationally. The Canadian match is brutal for international grads. So before picking your school, you need to be clear on which country you are actually trying to practice in, because that changes the whole calculation.