I think once there's a clear Big 2, ESPN and Fox will probably want to put more resources in the SEC and B1G, and all the other conferences will be squeezed for whatever they can get. We're seeing it with the leftover PAC12 schools. Schools outside of the Big 2 will still play sports, but it'll be more on a regional basis whereas the Big 2 teams will play national level type games.
There's long been a rumor that the B1G will ultimately "professionalize" their league once they are done expanding...which won't be until they pick off the ACC schools. Their new commissioner is a BIG clue how the B1G perceives itself. They are modeling themselves on the pro sports media model, and they will "acquire" the biggest markets and schools within it. No, they won't be a "professional" league in the purist sense, but they want to put together a sports league that rivals the media clout of professional sports.
Needless to say, over the next decade plus, the NCAA as we've known it will cease to exist.