Actually you'll see that if you check out our pronoun policy bulletin list there's some cool sources linked about the historical existence of neo pronouns in numerous different precolonial societies that you might find interesting

Edit: for anyone actually interested in the historical uses of neopronouns and different genders outside of the false dichotomy of male and female this essay from the anarchist library is a pretty interesting read https://theanarchistlibrary.org/library/vikky-storm-the-gender-accelerationist-manifesto though it might also help to read up about the concepts of base and superstructure first here: https://en.prolewiki.org/wiki/Base_and_superstructure