That'll never happen, Tesla partnered with Toyota on the Rav4 EV a decade ago and it did not go well. They have been adamantly opposed to partnerships with legacy auto makers since. They used to get alot of the interior bits from MB, but have since brought that all in house.
I assume you read this
article since you are quoting it. So you know how there are a bunch of fabs in work, which means that the folks who build them are in demand, and undoubtedly are wanting to be paid more. At the same time, fab construction in Taiwan has slowed, so I bet its easy to grab some cheap labor from there.
While the US may have 'only' 12% of the world semiconductor market, that is still a huge amount. Its not like Intel brought in workers from Taiwan when it built Fab 42 or Ti when they built RFAB2 last year.
Just because you have worked with some folks in the pipefitters union does not mean there aren't others in the union who are can do the work. Yes, there are a ton of pipefitters who do sprinklers, oil refineries, and HVAC work. But there are also ones who work in far more skilled areas. Its not like the same guys in the UAW who put tires on cars are the same ones who build aircraft and missiles.
Regardless, I'm sure a huge reason they want to bring in foriegn works is so they don't ahve to deal with the union, because while the skill level of the workers may vary tremendously, one thing that is always true is that dealing with a union is hugely expensive and a massive pain.