Posted: Sep 22, 2019 1:48 am
Shapiro is right that this is a new usage, but he doesn't really seem to know why. He also doesn't seem to know how dictionaries work. There was a discussion amongst linguists on this issue the other day on Twitter. They get lobbied all the time by groups who think that the dictionary somehow describes the definitive meaning of a word, rather than simply describing how people use the word. For example, when they changed the definition of marriage to include same-sex relationships, they were lobbied by Christian groups to keep it as it was. Typically a definition will only be changed if their's evidence of "widespread use." Basically, these people want to live in France, where a bunch of stuffy old men decide what is "proper French" and everyone just ignores them anyway. For the record, that video makes exactly the same mistake that is the topic of this thread. It uses examples of a completely different use of the singular they to claim that using it for non-binary people isn't a new thing.
The one thing that did come up though was how quick the dictionaries are to put changes in if the "widespread use" is amongst educated middle-class people (preferably journalists) in London or New York. Meanwhile words that are pretty common in working class communities or regional varieties can be in use for decades and still not get in. Just as an example, I looked up the word "hangin" which is pretty commonly used in Wales and has been at least since I went to uni there in 2002 (probably a long time before that too), but you'll have to find it in the Urban Dictionary if you want to know what it means, because apparently it hasn't reached Oxford yet. Meanwhile, the London slang "innit," which is in my experience only ever used ironically outside of London, does appear in most major dictionaries. So I'm not sure what criteria they use for when something gets put in the dictionary. There definitely seems to be a bias towards written English, as there always has been with grammar too, not because it's more valid, but because it's easier to collect samples and study them. That obviously means that publications and people who write professionally have a lot of influence over things (and that's why if you want to change the dictionary, you should lobby the newspapers, not the dictionary). Merriam-Webster says that "widespread usage" covers a wide geographical area, but most dictionaries will include words only used in a particular region. Oxford includes words like "kecks" and "wee" that are really only in use in particular parts of the UK, for example.