I'm not exclusively talking about people who identify as nonbinary in terms of their gender identity.

I'm referring to male students and female students whose interests/behaviors/personalities don't conform to what society has traditionally deemed to be "masculine" or "feminine."

You appear to be advocating a one-size-fits-all approach to how students should be treated differently in schools, based on their differing genitalia per se. That's what I was referring to when I said "binarism"/"binarist." If I misunderstood what you meant, please correct me so I can apologize.