Imo, just posturing. They ain't going nowhere. Some of the less-resourced programs in FBS might decide to compete at a more manageable level, but that's lower-end schools making their own decisions
At this moment Sankey and Pettiti and their school presidents may want two things above all else:
1) The ability to legalyl enforce rules in recruiting, the portal and eligibility, i.e. legislation in Congress to help put a lid on the chaos we see now
2) Collectively maintain a firm grip on power at the highest level of college athletics
Gotta believe Miami is too valuable to be left behind (and to the SEC/B1G cartel the Canes likely fall in the category of "keep your friends close, but your enemies closer)