Singular “they” isn’t just an issue for people with fluid gender identities, Zimmer said, “but I would say that the embrace of singular ‘they’ takes on added significance now that it is becoming a prominent marker of non-binary gender identities. And those in the media will increasingly need to grapple with these issues in a serious way.”
Question from ACES2015: Is it time to accept ‘they’ as a singular pronoun? | Poynter.
The American Psychological Society put the singular “they” into their stylebook about 25 years ago.