Appointees must report any significant change to their medical history, in terms of injury or illness, promptly. No indulging in magical thinking - appointees can and do get turned away at reporting in day.
This may result in a DQ and being directed to not report in. The appointee then works with Admissions on a readmission plan for the next class, which might include keeping them updated on medical status until getting recleared, talking first-year like courses at a local community college, reapplying for noms, etc. Ideally, something that looks like an LOA specific to their case is created.
That’s why the running joke is to break out the bubble wrap for appointees and hang onto an alternate plan as long as your personal risk analysis tells you to.
There is also the possibility the issue could result in a permanent DQ with no waiver.
Every year, someone tears an ACl, breaks a bone, gets appendicitis, etc., inside the no-go window.