"For those now considering commenting to suggest that there’s a perfectly fine existing neutral pronoun – “they” – remember that pronouns must match both gender and number. So in the case of single individuals, it’s grammatically inaccurate."WRONG. As we know, what's grammatical is what speakers find to be grammatical, including singular 'they' for most people. (Let's also overlook the fact that in saying that 'pronouns must match... gender' it precisely contradicts the point of the article, which is that we want a pronoun that isn't specified for gender.) Fortunately, someone in the comments section was there to help them out:
"If pronouns have to agree on number and gender why aren't you campaigning for new words to separate you (singular) from you (plural)?"
The technical term for this is 'underspecification': forms might be specified for number, gender, and person (first/second/third), and if any of these is not present, it's underspecified for that feature and it can 'match' with anything. So, for instance, we might say that you is not specified for number. In fact, it probably is, as it has to occur with the plural form of the verb (were rather than was, for instance), just like they does. And then of course in French the pronoun used to refer to 'you (singular)' is either singular or plural, depending on whether one is being polite (tu/vous) with appropriate singular/plural verb agreement.
This is a much more sensible article on the matter.