I think we're long past the melt away stage. Barely anyone caught SARS. It was actually contained. This has not been case with COVID-19.
I don't think the colleges have any clue, what they have decided is they don't want their students leaving campus for Thanksgiving and coming back, therefore spreading or acquiring the virus all over the country. College football is taking its cue from that, though if they really play a season it seems likely the athletes would simply not to get go home for Thanksgiving, since they'd have games that weekend (and the next one if they're on a good team). Seems unlikely they'll have basketball season.
With the NFL the worst case would be they play 10-12 games and then can't have the playoffs until the spring, pretty much the same kind of interruption the NBA and NHL had.