In 1985, Sting released “If You Love Somebody, Set Them Free,” the first single off his debut solo album, The Dream of the Blue Turtles, and immediately started take quantities of shit from the grammatically pedantic for using “them” as a singular pronoun. That was just lazy English, you see.
It’s now almost 2020, and in a society increasingly aware of and comfortable with the fluidity of gender, using “they” and “them” as singular pronouns is not only acceptable, it is often preferred.
I’m not ready to give Sting credit for being some kind of linguistic futurist, but what this evolution shows is quite simple. Artistry and creativity are more durable than pedantry.