Please reread the united nations document. It has nothing about referring to a single person as “they”. The only correct use of “they” is referring to the “undefined number of unknown people”.
“Before submitting your document, send it to the focal point for their review; they will return it to you with comments.”
Substitute judges must certify that they have familiarized themselves with the record of the proceedings
Personally, I’m highly against any regulations of the language.