For those claiming the idea of undetermined gender is something new in the modern era, I have some history for you.
Aristotle (fourth century BCE) had a different name for the three genders (Poetics 21): masculine, feminine, and “in between” (μεταξύ).
The Talmud, a huge and authoritative compendium of Jewish legal traditions, contains in fact no less than eight gender designations including:
1. Zachar, male.
2. Nekevah, female.
3. Androgynos, having both male and female characteristics.
4. Tumtum, lacking sexual characteristics.
5. Aylonit hamah, identified female at birth but later naturally developing male characteristics.
6. Aylonit adam, identified female at birth but later developing male characteristics through human intervention.
7. Saris hamah, identified male at birth but later naturally developing female characteristics.
8. Saris adam, identified male at birth and later developing female characteristics through human intervention.
Source: https://www.myjewishlearning.com/article/the-eight-genders-in-the-talmud/
You can find other sources listing six or eight genders from Talmudic studies. Apparently six of them are mentioned "hundreds" of times; perhaps the other two don't get so many mentions?