It won’t happen overnight. Either the blockade or the migration.

The seeds of the migration have been planted. TSMC is likely already concerned about losing employees to competitors. Of course, if they opened up new fabs elsewhere, they could keep those employees. Oh, wait. That’s already in the works.

Highly trained scientists and engineers in semiconductor manufacturing in the middle of a semiconductor shortage? Wherever the heck they want to go. The guys who worked on the Manhattan project ended up in the US. And there will likely be some warning before the blockade.