I think not only Korean investments. Actually I trained people in the US back in 2015 on the same visa those guys from Korea did this year, it’s kind of common practice in a legal gray zone. Getting the real proper work visa takes a lot of time and costs a lot of money while the projects need to start immediately. The visa we had allowed you to do business there for 90 days. It depends a bit how you define doing business, and if training your US collegues or a customers guys is working there or doing business. You still are payed 100 % in your country and not in the US. But yeah it’s a gray zone.
Now the people who were kind of forced to invest in the US to make money will have a hard time to find workers who would go there to do the training because they have to trust their company to do the paper work correctly. I would probably decline even though back then it was a lot of fun to do that project, and I did it again in Korea because I liked it so much.
But it’s not worth the risk, the money is not so much more and once you end up in ICE jail, you won’t be allowed in the US for tourism either in the future. The investors will have a much harder time to find the right and competent people to do the trainings there to such a degree that they will need to look to invest their money in other, investment-friendlier countries.