This is ironic if you consider all the complaining that Musk does in the public sphere about "freedom of speech" (I know that the first amendment only applies to government censorship, but Musk likes to pretend not to), but it's also significant because -
Smart journalists are going to stop relying on Twitter's API now. News and blog sites love to render Twitter URLs as a preview of the tweet; but if Twitter under Musk is going to start removing tweets that go against its corporate interests of the hour (is it against Twitter policy to post screenshots of any corporate Slack channel, or only Twitter's own?), then people had better take screenshots of the tweets they want to quote, just in case.