This is genuinely very upsetting to read. I've had more issues with the lemmygrad folks (who I am a part of) and it's only on the minutia of leftist infighting, not policy or ideology, and especially not on gender issues. Hexbears have been amazing, so I really wonder if this person is characterizing arguments that they disagree with as facile. I was lucky to have people show me where my reactionary tendencies were when I transitioned, but this is something else entirely.
Sorry for the rant. This frustrated me greatly, especially since like 90% of the hexbears I see are pronouned up trans people who kick ass.
Pronouns are mandatory. If I see none/use name default pronouns with a username I don't recognize, if there's a doubt they ain't getting the benefit. Like David Lynch said "Set your pronouns or die!"