I think you missed the point as to why your friend was banned. It is the use of AFAB which is problematic. It incorrectly assumes that postop trans women are not equipped the same as cis women. As a post op transwoman myself, I can state with confidence that my bottom is the same as a cis woman’s. It is anatomically and functionally indistinguishable. Because my hormone level falls into the range often typical of pregnant women, my surgeon provided me with a letter assuring my gynecologist that no, I was not pregnant, merely trans. She could not tell the difference upon close physical examination.

What I think your friend may have intended to say, giving her the benefit of the doubt, is that she would have no interest in a pre op or non op trans woman because her equipment was not her preference—and that is ok. She likes vaginas only. Nothing wrong with that. That is merely a matter of personal sexual preference. What was not okay was to equate gender assigned at birth with whether a woman is authentic or not. Trans women are women. Trans women who are anatomically female should be potentially just as attractive as a natal female (assuming all of the other elements of attraction are met such as compatibility, appearance, chemistry and the like). To reject an otherwise anatomically correct partner solely because her gender assigned at birth did not meet some irrelevant arbitrary standard is not a matter of preference. It is simply transphobic bigotry, and that is not okay. That is why your friend was banned. It had nothing to do with sexual preference.