The definition of lesbian cant change and hasnt changed, no matter what the power dynamics for cultural appropriation are. It's no different then people trying to say the word "gay" has changed (when it really hasnt) because some straight or bi girl who colours her hair calls herself gay when gay just means a homosexual man. They didnt exactly contribute to creating the movement, or the word or anything and they sure as hell stayed away from it when it was associated with pedophilia until gay men were the ones to clear that up through incredible sacrifice.

Homosexual females needed a word just like homosexual males had one for themselves, so lesbian stuck. I highly doubt the word "gay" has changed or fluctuated simply because some people think it's up for grabs. The only thing that they've really managed to contribute is destroying the image of lesbians as man haters and women who are "sexually fluid" but hate men so it's more political...damaging the notion of homosexuality itself.

Lesbian, like gay, isnt getting narrower as if these people were allowed to identify as such in the first place. It's just that the word lesbian (especially the word gay) has such a gigantic, gargantuan and colossal weight to them that people like twisting and appropriating them because they have no foundations of their own to start since they dont want to lift a finger to do any hard work or sacrifice for themselves and other people that will come after them. Thats called a community. Thats the very essence of a community.

But im sure "people take the path of least resistance", so let gays and lesbians do all the hard work.