Well, yes and no. I think she does owe her intellectual development to our contemporary revaluations of earlier lesbian subcultures. I think that at the height of the second-wave feminism, butch/femme things may have been looked down upon, judging by what, for instance, Susie Bright writes about them. It was politically incorrect to do those gender plays, because back then the thing to do was either to be a 'woman-identified woman' (think Rita Mae Brown or Adrienne Rich + her lesbian continuum) or to look forward to a gender-free future (e.g. Shulamith Firestone). Or at least so says Bright and many others of her age. In other words, 2nd-wave feminism itself also created rigid identities for 'right-on' feminist women within which what's taken as signs of patriarchy--butch/femme--and also of blue-collar lack of sophistication were not welcome, or so the story goes (I can't provide any personal testimony--I was too young to be part of anything). So I think that Butler's invoking the 'Lesbian Phallus' is her nod--debt and ambivalence--to the history of feminism and lesbians' places in it, not just its sexiness.
By the way, several guys have asked on the list what Butler said that was truly 'new and original.' As you can see from Liza's post, a part of What Butler Saw may be summarized thus: lesbians are not 'fake men -- if we are, then men are also fake men'; moreover, the notion of Original which Copy is said to imitate is a phantasm _retroactively_ created by casting some as Bad Imitations.
Yoshie