It leaves us with 2 paths forward. The first, and conservative path, is to maintain the old categories, and to maintain their validity as well, but to allow switching between them. It is a “progressive” view only in relation to the slightly more conservative view that you can’t switch between them.
It is conservative because it is geared towards conserving the validity of these identities, and gives a residual share of validity to those who embody them.
The second, and seemingly more unsettling, path is to follow the phenomenon to its logical conclusion; that all of these identities are equally invalid. They don’t serve us, they capture us, and they are doing bad job of it.
Gender has become one of those things that is so far separated from its initial construction that we don’t treat it as a theoretical device but as a natural fact. We’ve built so much on top of it that undoing it will certainly cause things to collapse.
But all that will collapse are just further intensifications of invalid capture. A gendered world exists only to reinforce invalid capture via gender.