Fans will still watch. Just like they watch now even if their school or their conference is out of the race.
Middle Tennessee State alumni grew up UT fans. Just because they didn't end up going to school there, they don't stop cheering for the Vols. Tulsa alum probably grew up mostly OU or OSU fans. So, they aren't really being cut out.
I don't think the rest of the NCAA is going to lock out the two Super Conferences of March Madness. That would kill the cash cow.
So add the other 12 brands that still pull in the lost money when TV agreements are over around 2030 and formally create a new tier of CFB.