Comment by lossolo
These workers didn't create the fab equipment and don't know how to design or create the machinery used there. They also don't have access to the software source code. Most US workers hold maintenance or managerial positions, while those with the deep technical expertise come from Taiwan. There will be no knowledge transfer, aside from how to operate the fab, which is something Intel US employees already know.
Fab equipment is made by other companies. Such as ASML:
https://en.m.wikipedia.org/wiki/ASML_Holding