Honestly, if I didn't read Hacker News and get exposed to this stuff I'd assume someone asking to be called "xe" was obvious trolling. I mean, who spends time inventing a non-existent gender with a word that is equally non-existent and then flames everyone for not using it? That sort of thing is classic trolling behaviour.
I've met lots of people who use these pronouns and I've never seen one go on the attack because someone got it wrong unless said person was an asshole. You should eject xem from your life. That kind of behavior is toxic and contrary to helping people learn.
This is clearly something very culturally local. I've never met anyone who uses such pronouns. I'm not even sure I've ever met a transgender person at all. If I did they didn't mention it and it wasn't noticeable.