The purpose of Twitter is speech. People like Musk argue it is analogous to a public space. Twitter users don't work for Twitter and are not subordinates of Twitter. Do you also imagine that Musk believes service people ought to be allowed to mock their superior officers to their faces without repercussions?

Maybe freedom from Twitter censoring you, but not freedom from repercussions from what you said (or tweeted). That’s ultimately determined by e.g. the courts and (as in this case) employers.