StackExchange is more than StackOverflow, and StackExchange is more than just the main site. Third party pronouns are widely used in meta and chat.
A new user will typically arrive at SE for asking or answering specific questions. Even most of the users with accounts rarely seem to go near meta and chat.
When I was active on SE (I gave up logging in a few years ago), meta was the afterthought to bitch about some policy or detail and the annoying habits of questioners. The chat usually empty or quiet enough that even looking to see if it was active seemed mostly pointless. I'm sure it's grown since, but that's not really where new people are going.
People are making a huge deal out of nothing.
For 99% of questions and answers pronouns are irrelevant, and rarely ever seen.