At least this person isn't using the made up xe/xir bullshit.
I still stand on the ground that first and second person pronouns are genderless, and 3rd person pronouns are for the benefit of the speaker and listener, not the object being referenced. So "preferred pronouns" is a narcissistic way to try and compel attention/thought into a situation that just needs simple clarity.
If person A and person B are talking about person C (person C being the whatevergender person) and person C has a vaguely semi-feminine appearance, then A will say "give the ball to her" to person B. If person C looks vaguely masculine, then A will say "give the ball to him."
When person A says "give the ball to xir" it just brings on an error-404 in person B. C's feelz don't matter, the point of pronouns in this type of 3rd person speech is rapid proxying of a complex proper noun object to a single easily understood reference. Complicating pronouns just mean they don't get used and everything becomes a proper name instead.
I also stand on the ground that "they" is a plural pronoun and inappropriate for singular 3rd person usage. The correct singular nongendered pronoun for 3rd person use is "it" but most humans find being referred to as "it" to be degrading. Almost as if one's masculinity or femininity were a component of their identity, and being deprived it is deliberately insulting.
Which brings up a weird point about the made up pronouns, xe/xir/zhe/zhir/etc. They're all rough riffs on he/she/him/her. There's vague echoes of the masculine or feminine in each of them, and the choice to choose one is still basically choosing "he" or "her." Which entirely negates their point at all.