Many different things can cause a person to faint and not all of them will result in a permanent loss of licence.
Virtually all of them do. No authority is going to take a risk on it happening again. In one or two of the airlines I have worked for, any such event would be instant suspension and eventual dismissal on medical grounds. Airlines don't want to take the risk either. Severe gastro is probably the only one you could get away with.
Sure, leave it to the medicos, no problem with that. However it is a salutary warning to all pilots to not get themselves into a situation where they might get sick during the flight, and morno's scenario should ring a few bells with most of us!
Agree on the global warming idea though.