The question is, was Elon Musk really the one who posted that?
It was his account anyway but I think you mean that his account might be hacked? This is possible though, especially on Twitter, as I saw a couple of cases like this too before.
It's easy these days to create an account with Elon Musk's name on it, as long as I know that when anyone in the X community reads something, they will immediately follow suit. For example, if they see someone with Elon Musk's name on it, they will definitely buy it.
No it isn't because firstly, the name has been taken already and then secondly, the original one has an indication that it was the original like a small blue or gold check mark. Only naïve people will rush and hardly notice the difference.
That's the role of the X platform honestly speaking, now whether he's a shiller or not is up to us if we believe it, and besides, I'm not a fan of Musk either,
so I don't care if he's like that or not.
Of course not but X is primarily a social media which aims to connect people all over the world. If someone wants to shill something, there is a proper place for it. Elon is a businessman and I won't say that he is an official shiller. Maybe he only does something like that for fun and to see how people will react on it.