We all have a different definition of toxic. HN gets really toxic sometimes, but it goes with the ideology of the site, so it’s like nobody notices. And that applies to all platforms, including Twitter.
It's usually couched in sophisticated-sounding faux-intellectual language, though, which is the key to posting whatever you want here. You can say literally anything on HN, so long as you camouflage it with SV techbro vernacular.
It must be some "ist" of you to assume it isn't transmisandry instead.
(And not sure that anything related to gender identity specifically divorced from sex is "sexism.")
This means your threshold is fairly low.
You're allowed to have those opinions, of course. We can talk about other things.
An outright refusal to use a common word is not a liberal trait.
This is you, happily using a singular they. Like every english speaker, you are happy to use it when you don’t know the gender of the person you’re speaking about, or it is irrelevant. If i was to talk about you to someone else i could say “they don’t like using preferred pronouns” because i don’t know your gender.
That’s all that’s being asked of you. Don’t assume a gender. If that is uncomfortable, perhaps you should explore that discomfort, instead of running away from it.