It's tricky. Not everybody _wants_ be called they/them. Not everybody wants to be called he or she either. The way I try to work around this is to use "they"

It's tricky. Not everybody _wants_ be called they/them. Not everybody wants to be called he or she either. The way I try to work around this is to use "they" only when it would not sound grammatically unusual or confusing to do so, and otherwise rearrange the sentence to omit the pronoun. As an example of the first, "That's their phone on the table" sounds natural because singular "their" is a lot more common than singular "they", and it's unambiguous because a phone is typically owned by an individual. As an example of the second, "I met Bill yesterday and they went to the store with me" is odd because it sounds like "they" either doesn't agree with singular "Bill" or refers to some earlier plural antecedent, so I'd rephrase it "I met Bill yesterday and we went to the store together" or something like that.