When I first got into the copy-editing racket, back in the early 1990s, writers, and thus copy editors, were vigorously wrestling with the longstanding and essentially rote use of the pronoun "he" to refer to a person whose gender was, in the moment, either unknown or irrelevant, as, for instance, "Is it wise to feed your baby whenever he is hungry?"
The commonly held notion that this allegedly genderless "he" did the job just fine because the default person is a "he" and everyone else can just fall in line behind that had stirred resistance from some writers. For a while, they were leaning hard into the use of "he or she" (which over time uses up a lot of space and, more to the point, can become quickly tiresome), alternating "he" or "she" paragraph by paragraph (well-intentioned but clumsy) or sentence by sentence (dizzying), with the occasional foray into "s/he" (just plain unsightly).
Clever copy editors would do what they could to address the issue, pluralizing nouns as possible to lead gracefully into a "they" or (one of my preferred tricks) revising a bit of text to eliminate the need for a pronoun entirely.
Funnily enough, I rarely encountered a writer reaching for what we call "the singular 'they,' " as in, "Is it wise to feed your baby whenever they are hungry?" It simply wasn't — again, in my observation — done.
Well, now it's done, and often. The dictionary folk at Merriam-Webster last week named "they" as word of the year, and not simply in its singular sense — Merriam-Webster helpfully noted that the singular "they" has been "used for this purpose for over 600 years" — but also in its nonbinary sense, as a third-person pronoun used by people who are gender-nonconforming. The editors also noted that in 2019 "they" look-ups on the company's search site increased 313% over the year before.
The online responses I've observed in the wake of the Merriam-Webster anointing have run the gamut from but-of-course embrace to outraged rejection, with a lot of tactfully, earnestly expressed confusion occupying the middle ground.
The embracers are fine, then, where they are, and the outraged parties can carry on with their outrage with no assistance from me. It's to the confused folk in the middle that I, a word person by trade, would hope to offer some advice and perhaps even comfort.
Yes, this nonbinary "they" use can be, as new things are wont to be, confusing.