TSMC understands the American workforce; they would not go into this venture with unrealistic expectations. Of course any company wants the best qualified "best of the best" but companies have to deal with reality.And
All I can say is, W-T-heck? I don't know foundry stuff, but I can't imagine it being any more OTJ training than any other job. You get good at it by doing it--start in the field young, the equivalent of being the guy walking mail around and work up. Head into IC design, that I do know a bit more about, and it's kinda foolish to spend a year plus training anyone, not when typical retention is around 5 years these days. Bad ROI. Maybe in Taiwan they can count on retention, but in Silicon Valley? err, that's nearby, but you get the idea. Unless if they are holding a carrot out in front of people fresh out of college, I can't see anyone in their 30's (or more), with a family, house, usual trappings, wanting to spend a year (a year!) overseas for training.
We do have a few foundries in the US:
List of semiconductor fabrication plants - Wikipedia
en.wikipedia.org
The CA University system generates more engineers than anywhere in the world. Sure, they fuel Silicon Valley, along with many more candidates from around the world. We are the most diverse place on earth.
My guess is, a lot of qualified people around here will jump for that cheaper housing market, especially newer graduates. I think you know, the machines that operate the fabs are designed here; my career was at Novellus, now Lam Research. R&D and Pilot lines are still built here, but the production semiconductor equipment is moving to lower cost locations.