'They' isn't used as a singular pronoun in many style guides, including the New Yorker's but nice try.
Re:How AlphaZero Mastered Its Games
by pie_hacker on Saturday December 29, 2018 @10:17AM
(#18783934)
Not in my experience...
I have noticed that people who exclusively use "his" rather than "her" or "their" tend to be men though.
The "Patronizing 'Her'"
Almost invariably, when the author decides to use the patronizing 'her' instead of the gender-neutral 'they' it's written by a man.