Is this a jab at (supposed) American racism/xenophobia? Because by definition I'm pretty sure being a native speaker is not a requirement for being an expat
>An expatriate (often shortened to expat) is a person who resides outside their country of citizenship
"Expat" is mostly an English (British) thing, much less US. I'd have called it by name, e.g. US exceptionalism/centrism, if that was the case. ("Expat" use rose during the British empire)
In the hypothetical case of a Romanian working in the US, "immigrant" would be a correct term (unless they obtain the green card and become a citizen)
Expat and immigrant are effectively the same thing under most jurisdictions... yet expat carries less stigma and people would prefer to call themselves that way.