Unlike almost every other CEO, Musk uses social media like Twitter to market his companies and himself and to make statements that benefit him and frequently attack various governmental agencies like the FAA. I think he see's Twitter as a means to an end. If he allows Trump and others that have been banned back onto Twitter he will ingratiate himself with Republicans and perhaps enlist them to help him deal with the FAA. And I can see it working. OTH, if something bad happens, like, say for example, a crash of Starship into or near South Padre Island, then he could find himself in much the same boat as Boeing did with the 737Max fiasco which implicated the FAA for, ... wait for it, not doing their job.
It may also be the case that Muck think's he has some ideas to make Twitter bigger and better and that could sufficiently increase valuations to make it worth it to him. With as many Musk-ites as there are that champion him as a once-in-a-century genius the mere fact that he makes a change could raise stock prices substantially.
I can't quite see how this would make any significant difference to Starlink, but we shall see...
Brian