AP stylebook now allows the "singular they" in some instances

You have put it well. Gender neutral language is a worthy and long-sought goal.

Beyond that, a small minority of our population would like to be recognized, through the use of pronouns by others, as not falling clearly on one side or the other of the gender binary. This seems like a step past the long-understood goal of ameliorating sexism in language. It is, of course, deserving of our attention.

Changing common usage is an inevitable part of the evolution of language. Some changes come about through the revelation that a coinage fits a need; others result from a political movement or mandate (nb: persondate would be an overreach here, given the etymology).

“They” used as a singular is the fix being discussed here. Of course, anyone who is sensitive and interested in the comfort and happiness of others will accommodate them in this matter. One wonders, however, at the further ramifications of this pronoun choice. I still have questions.

Once upon a time, it was common in published material to alternate “he” and “she” as the third person singular pronoun. This was considered sufficient fairness and gender neutrality. It is the standard I have followed in work I have written for publication in English. Must one now change that standard? What should the change be? To alternate “he,” “she,” and “they?” Circumlocution to avoid the singular entirely?

The second thing I still ponder is the gender neutral reflexive pronoun. Ought one to step further into the unavoidably plural with “themselves,” or should one popularize the awkward coinage “themself?”