"${LANGUAGE} programmers" aren't really a thing. Our important skills translate fairly cleanly between ecosystems.
I am willing to bet that most of those “Rust advocates” are programmers who code in Rust but I’m fine with not calling them that. I agree that good programmers should be able to work in different languages, operating systems, countries.
For example, if this had already happened we may find today that Java is certified for use but that Rust is simply not allowed, while maybe Swift is because of Apple's backing of it.