It was an E-2 visa (as "essential manager", not investor...), so not H1B. But again, that's what the attorney told me, maybe he just wanted to be super extra careful. But notice the nonimmigrant wording on the U.S. Citizenship and Immigration Services website [1]: "The E-2 nonimmigrant classification allows a national of a treaty country...". My employer did propose to sponsor a green card application, so I had a path to permanent residency. I wasn't interested: I had the firm intention of going back to Japan.

Anyway: my point is that "immigrant" and "expat" are not synonyms: "immigrant" has a much narrower meaning, which has absolutely nothing to do with coming from a poor country or a rich country.

[1] https://www.uscis.gov/working-in-the-united-states/temporary...