Completely wrong.
You act as if you have the math figured out.
The reality is that there will be seats, even if some of them are in the Big 12. The Big 12 is ALREADY poised to pay out more money PER SCHOOL than the ACC currently does. So even if some of these schools become the east-coast branch of the Big 12, they will STILL make more money.
You act as if the Big 10 and the SEC are the ONLY choices. And for Miami, that may be true.
But not for everyone. Duke and Wake will do VERY well in the Big 12. Louisville and Pitt too.