No, he didn't. If he did, the company wouldn't be suing him, since he would control it.
I think you’d correctly say he bought the company but has not settled, so he does not yet own the company.
a distinction without a difference, he doesn't own anything beyond the board seat that his equity holdings afford him.
a distinction without a difference, he doesn't own anything beyond the board seat that his equity holdings afford him. Vanguard owns more of Twitter than he does.