Depends how it plays out, and there are some assumptions built in to your reasoning. Considering there are teams in California in the Big Ten, I think expansion into something closer to AFC/NFC is what the Big Ten/SEC are headed towards. They are close already.
And what fans like is winning, if teams in the southeast win, fans will show up and ratings are fine as it is. Considering Kentucky and Indiana are in “those regions” and are basketball schools - it’s a dubious premise to begin with that “those regions” don’t care about basketball.
The question is if Penn State and Rutgers represent the northeast adequately. And if not, is adding BC to cover New England good enough. Syracuse matters if it’s a high level program - right now we’re just a Rutgers peer with potential to draw ratings in NYC without the actual ability to do so. We need to do everything possible to win and be attractive as changes come in college sports.
I don’t know exactly what it will look like, but some collection of 32 to 64 teams breaking away from the NCAA would be my bet. It won’t kill the sport, it won’t kill the attendance, and it won’t kill TV ratings if it happens. It’s not great that instead of trying to prepare for that possibility, we have fans longing to return to the Big East.