I mean all things considered, pre-Musk buyout, Twitter was largely the least moderated of the major social media sites I'm aware of. Yes, people constantly brigaded and flooded the like buttons, but unlike Facebook groups or subreddits, users couldn't ban other users comments, so you'd just have to accept the extremists.
So if Musk literally did nothing but continue that pattern, he could justifiably make the claim that it's as close to a bastion of free speech as could be allowed on a social media site of its size.