Obviously the relevance of any given regular season is directly proportionate to the percentage of teams that make the post season. NHL and NBA have proven that in spades. Hard core fans only. Football and baseball have been measured in their playoff expansion so not as bad. That said, even with a lower percentage, the regular MLB season may be relevant but it's still boring.
Once there's 128 teams in the dance the college hoops season will be even less relevant.
But diluting the college basketball schedule further is not going to increase the value of college hoops. There's more than enough games to televise nightly so I wouldn't expect any significant media rights increase by playing more. College football, and football in general, is what it is, a media rights monster. Hoops isn't catching up. Football teams are still just playing once a week as far as I can tell, college hoops teams twice a week on average. That's just about right.
So with an equitable competition/school balance and a dubious prospect of generating any significant incremental revenue what do the schools have to gain by extending the season.
And I didn't even try to raise a "student athlete" argument. I know better than that.