Given extensive archaeological and anthropological evidence for the existence of enormous amounts of gender fluidity and variance throughout history and across the globe, it'd be more accurate to say that the imposition of a strict binary hierarchy upon history/pre-history constitutes a "reactionary conservative utopia"
Anyway what surprises me is, despite the supposed existence of six genders and accepted homosexuality is that none of these things get mentioned outside of the little blurb at the beginning of the book. Going from real world examples, you'd expect to see more cults and cultures with codified roles for gender-variant people, at the very least some eunuch-only priesthoods, things like that; as well as actual named characters in same-gender relationships mentioned in the text. But.... well, "surprising" is the maybe the wrong word. Disappointing and expected, perhaps.
But hey, YGMV; if you want to base your Bronze Age on the self-censored writings of squeamish Victorian archaeologists (who'd regularly destroy/leave out artifacts they deemed "immoral" from their reports), well, nobody's stopping you.