>labor shortages
There are more than 300 million people in the US. This is definitely a shortage, but this isn't a "labor" shortage. This is a "we're not willing to pay you enough why does nobody want to work" shortage.
Counterpoint - sending people from TSMC that already have hands on experience will make things much easier for them.
If they only want people like that, then yes, they can't just divide the facility in two, like a cell. They'll need to train more.