I agree with just about all of this. I think there will be 2 main drivers that reduce the number of schools who play: money and injuries. Schools on the coasts will opt out because football is dangerous; they may try to start playing with much different rules that dramatically reduce injury risk, but I don’t see how that will appeal to enough people to generate the same money. I half expect soccer to take hold as the main sport in those areas. Smaller schools will be forced out because they won’t be making money; some of those schools may field teams that play at a lower level with unpaid players, similar to the old days.
To your point about the ability to opt out of classes, I don’t think that will be necessary; I think there will be degree plans made up that allow athletes to get credit for all the training activities they already do and will let them out of attending lower level coursework where they have to mingle with all the other students. Those degree plans are pretty much already in place, I think they will just be taken the rest of the way such that all these guys have to do is practice and play football.
I do think the NFL’s popularity will be a leading indicator for college football. As long as the NFL remains popular, there will be enough demand to keep the 30-60 most viable schools going.