Miami back in the 70s was seriously considering dropping football. Now they control it.
Tulane was once in the SEC but voluntarily left. They are now considering dropping football and may well do so.
Holy Cross was once in the BE (or at least I'm pretty sure about that) ansd now is barely known outside of New England.
We used to beat the snot out of quite a few schools in the Big 12. Now we are in some idiotic conference, made possible by the breakup of the SWC and the WAC Goats.
Life is like golf: it is hard and unfair.