I dont believe it is possible to regulate free speech, it is either free or not. If Elon doesn't do the same pump and dump trick with Twitter as he did with Bitcoin, he is effectively putting a noose around his neck that he can't win, as he either has to succumb to some very heavy pressure to "Regulate", or allow some very harsh profit-damaging truths about his own empire to be publicly discussed.
Either way, interesting times!
I wrote some more here:
https://link.medium.com/zNnno42szpb