[filoleg]

Oh god, the more I read, the more I actually think your guess might be correct.

Even OP himself, once questioned, didn't really deny, and was just going around the fact by saying he doesn't know why he got banned, and that he wants to figure out whether he did it as well.

On top of being "totally certain" that no one got unauthorized access to their account, all while having no 2FA set up, I just give up my attempt to bother understanding some people. I have zero idea how it is possible to tweet something and then not being able to tell whether you actually tweeted it yourself when presented with a screenshot. But, from what I am seeing OP say in the thread, it seems like a very strong possibility.