The Phoenix fab is extremely likely to be a disaster. Even besides the cost of labor and incompatible work culture, the whole idea was a political concession to the US to begin with rather than genuine interest on TSMC's part. You can already easily find reports of discontent and setbacks, and that's just what's available in English.

And I suspect you would be sorely disappointed with how many would be interested in packing up shop for the US, if it came to that. SMIC and others already have success luring engineers to the mainland.