Customizable pronouns

[cinnamonoreo]

It is still heavily argued to be plural. Even if it was used back in the 14th century, it can just be argued that those works were grammatically incorrect. Shakespeare does that a lot. Just because it's old doesn't mean that it's correct. Hopefully, in the future it will be adjusted so that it is widely accepted as singular, right now, it is not. You'll still get marked down for using 'they/them' as singular in papers for example.

It's very widely accepted as singular. You just rarely notice when you use it as singular until someone makes some noise about it. We naturally use singular they when referring to someone whose gender we don't know, for instance. Arguing that it's exclusively plural is fairly recent historically.