It is enough of a digital town square that politicians from local all the way to federal make proclamations on it, as well as there being legal precedent prohibiting politicians from blocking their constituents.
Federal what? The Russian federation? Also, why are people constantly attempting to compare a website to a square in a town?
(for those not reading between the lines: most of the world doesn't live in the US, and most of the world also doesn't assign special privilege to town squares, digital or otherwise)
The last bit of the second paragraph would of been a fine comment on its own without the snark.
That aside; this is an American website discussing an article about an American company having a ruling made against them by an American organization based on actions they took in America. I don't think the rest of the world is relevant to this discussion, and I don't think you do either.
To add more details, the legal precedent on this only says government accounts' posts and account pages are their own public-square-type place, not the entire Twitter service. Personal accounts when used for government-like purposes by government officials count too.