Those terms are widely understood.

This is widely understood amongst most Americans, not just the gay community. I would assume this is also the case in most English speaking countries (at least amongst those who know gay people or watch television or film with LGBT characters).

I live in the United States, I'm not gay, and I understand them. They go back at least to the 1970s. I would expect an ordinary English dictionary to include them, let's check. https://ahdictionary.com/word/search.html?q=femme Femme, n. 1. Slang: A person, especially a lesbian or a gay man, who exhibits stereotypical feminine traits, often in an exaggerated way." https://ahdictionary.com/word/search.html?q=butch Butch, adj. Slang: Exhibiting stereotypically masculine appearance or behavior. Used especially of lesbians and gay men. n. 1. Slang: one who is butch. Incidentally, like you, I thought they applied only to lesbians, but the dictionary says they are also used for gay men. That's news to me.