I have well meaning people at a party who are trying to describe their friend who is supposedly gender fluid but they dont really know how to talk about them? Do you just refer to gender fluid people as they/them until they tell you how they feel that day/week/whatever? Do you refer to them as what you last were calling them? Id look it up but im very drunk and i dont teuat googlr in this state lol
Either one could be ok, depending on what the person you're talking about prefers (their preferred pronouns). But since you're asking, it sounds like no one participating in the conversation knows what this person's preferred pronouns are. So again, either one should probably be ok, so long as it's made clear you all have respect for this person's identity, even though they're not around to specify their pronouns. They/them is probably more universal and generally accepted rather than using their assigned gender pronouns, so if they're not there to verify, it's likely the default to go with.