In the context of this thread, I thought: if I don't want the machine to presume male or female, than what do I want it to do? he/she was what I came up with, but this does not address non-binary gender or fluid gender, weaknesses which were on my mind.

Curious, I looked for guidelines and the best I could come up with was this, which seems helpful if you know the person in question, but not so much if you're referring to someone completely unknown: https://en.wikipedia.org/wiki/Third-person_pronoun#Transgend...

I welcome advice.

Sure, I'm glad you asked.

Singular "they" has a long history of being used as a generic pronoun, before a bunch of white men decided in the 18th century to try and prescribe "he." Singular "they" is making a comeback, though, and in this case it would be appropriate.