Male and female is a binary we as humans created to classify people scientifically and socially. There have been people to don’t fit into that classification since people walked the earth, it’s only now that we’ve expanded the classifications to more accurately reflect the complexities of gender. Nothing has changed except our understanding of gender and what makes us what we are.
What you’re arguing is tantamount to arguing that Pluto really is a distinct planet because that’s what it was classified as upon its discovery, that’s what you learned, and thus it always shall be until forever. The reality is the criteria that defines what a planet is expanded upon the discovery of other celestial bodies in that neighborhood, and Pluto no longer qualified in the new classification.
Nothing about Pluto changed. We just learned and discovered more. Those discoveries required our classification of what makes a planet to change, which restructured our solar system, which resulted in Pluto being reclassified.
Besides which, non-binary gender has existed in the animal and plant kingdom for a millennia. It’s not like non-binary is a recently invented classification, just that we now know how it applies to us, too, and how it’s not an aberration, but a normal state of being and our classifications have flexed appropriately.