Free speech is a multi edge sword. It gives radical ideas an avenue for discourse. We have been used to left leaning radical ideas since the 60s and the general centrist leaning consensus is inclusion. But Trump and co have pulled the sheet off the radical right ideas and somehow made them almost mainstream and today's great American schism revolves around what free speech is.
However much I dislike right wing discourse on most social issues, I think it's important not to stifle those voices, precisely because extreme ideas usually propagate in the dark. The public square ought to dare all to speak up.
I think Musk believes this and wants Twitter to be the public square, without subjective minders to control the square. However, he (and I) believe anyone who speaks must take responsibility for their words and he aligns with European rules on free speech: anyone who speaks must be identifiable, and anyone who slenders must be ready to face justice. With great rights come great responsibilities.
Musk also wants to rid Twitter of the propaganda machines that overwhelm the square, from 2 bit peddlers to powerful dark money. The square should be an avenue for discourse, not an MMA hexagon.
So yes, I think Musk is driven by a fundamental common good goal. He also believes that if he can make money from it, even better.
No social media board has succeeded in this. Four-chan, Trump's thing, etc. All that claim to be 100% free speech have to start censoring otherwise things go Lord of the Flies real fast.
Look at how much moderation Baron has to do to keep bots from advertising. Technically he's stifling free speech in a public square.