Yeah, if lesbian means Woman who is sexually attracted to only Women, then a non-Woman/non-Man entity does not qualify as a lesbian. They cannot use this label.

This works for me as an exclusion argument, given that the point of every non-binary person I've ever encountered was to uwu let everyone know how they were better than people who use "male" or "female" to accurately describe their sex.

Logically speaking, non-binary people shouldn't want to have anything to do with LGB.