This, together with Musk personally pursuing people out of what can only be described as pettiness, is why I have a hard time imagining him not abusing his new power to silence people he does not like.
A person that sends private investigators after rescue personnel that doesn't want to participate in his PR stunts [1] just to dig up any dirt on them, personally cancels Tesla orders of bloggers [2] and calls the bosses of critics to silence them [3]. Musk is all about "cancelling" people if he doesn't like them, and the bar for that is very low if you include all of his childish tantrums on Twitter and how he sends his always angry (and cultish) fanbase to harass anyone over the slightest comments he interprets as negative.
Free speech under Musk will probably only be applied very selectively.
[1] https://www.theguardian.com/technology/2019/oct/08/elon-musk...
[2] https://www.theguardian.com/technology/2016/feb/03/elon-musk...
[3] https://www.inverse.com/article/47461-elon-musk-responds-to-...