Back in 2014, "he" was still considered by many to double up as a gender neutral singular pronoun (which was the standard in English for at least a century). The rehabilitation of "they" as a gender neutral singular is very, very recent. I had to be actively taught not to use it that way back in the late '80s.

This, of course, was the proscriptivist position. Kids who "don't know any better" have always used a gender neutral singular "they" until their teachers told them not to.