Looks like Twitter.com/Bitcoin is r/Bitcoin now.
Did he answer why he change his side to BTC? That's a full right outta '1984' doublespeak going on there.
it's 99.999999999% certain that the original owner sold it.
If you watch the latest video from Bitcoin.com and Roger on the beach, he talks about the twitter account and implies it was maliciously taken from the original owner.
Unless the person/organization that took it has threatened him somehow. Say it's twitter and they will give out his identity if he says anything or blockstream has something on him.