If someone is a racist bigot, they shouldn't be physically restrained(deleting posts is like physically covering someones' mouth) from being bigots but they should definitely be known for it. Then it's up to the community to decide how to interact with those people. That's how we do it in real life and works pretty well.
Another thing is the amplification: people pretending to be multiple people. This is also an issue, giving wrong impression about the state of the society and must be solved.
Lastly, we need some kind of spread management. We have the problem of BS getting huge traction and the correction getting no traction. Maybe everyone exposed to something should be re-exposed to the theme once there's a new development. For example, when people share someone's photo as a suspect and it turns out that the person in the photo is not the suspect, the platform can say "remember this Tweet? Yeah, there are some doubts about it. Just letting you know". The implementation of it wouldn't need a ministry of truth but an algo to track theme developments.
IMHO if Musk manages to solve these few problems, which I think he can, a free speech social media is possible.