First, I really doubt kansas (or any Big 12 school, except maybe ISU) ever gets left on the outside looking in like that. If it comes down to it, the Big East will take the leftover Big 12 schools (they were prepared to last summer).
Second, even if kansas did end up in a second rate conference, he's freakin' Bill Self and he coaches at kansas. His contract wouldn't change. Their fans would make sure of that. They'd cut every non-revenue sport if they had to if it meant keeping basketball relevant. And even then, in a worst-case scenario, he'd have his pick of any coaching spot anywhere if that happened. He doesn't need to get out ahead of conference shakeups. He'll be in demand no matter what happens.