I know people who identify themselves with plural pronouns, e.g., “they/them,” but I’ve never heard any of them refer to themselves with plural pronouns, e.g., “us” or “we.” They always say “I” or “me.”
A couple of possibilities, not mutually exclusive:
- They want to call attention to themselves but in a way that they haven’t really thought through.
- They realize how ridiculous it sounds to refer to an individual person with a plural pronoun.
I mean, go ahead and call yourself anything you want, but if you’re going to burden others with absurdities, you should have to live with them yourself.