Category talk:Gender
From BDSM Wiki
I don't know and can't find much about Evolving in terms of gender, seems like a synonym for Gender Questioning to me, just by the sound of it. If someone more knowledgeable wants to contribute that page, feel free to. For now removing it from the future page listings though.
Didn't see it earlier, but it was combined into Fluctuating/Evolving, so adding two redirects now.