[Forbo]

There's definitely science behind it, it's called stylometry: https://en.wikipedia.org/wiki/Stylometry

Here's an example of an open-source project designed to counter stylometric analysis: https://github.com/psal/anonymouth

With how much caution they are taking against a nation-state adversary, I think it a bit short-sighted to think that this is just "a racist idiot's idea of a joke".