They’re NOT preferred
It’s #PronounsDay, and I want to take the time to remind people that pronouns are not preferred. While this may have originally been the language used, that’s changed. Because ultimately, you are not being asked to use these because it’s a preference of theirs. They are the pronouns you should be using, or else you are misgendering them, and you are ultimately disrespecting them.
So don’t be the person who tries to make out that pronouns aren’t valid as they’re new pronouns, or they may have traditionally only been used as a plural. Also, if you’re trying to say they/them/their can only be plural… well, what happens if you’re asked, “Where did they go?” — I’m sure you’ll agree you’d be using context to tell you if it’s a singular they, or a plural they right.