>Getting companies to not delete posts if they want to not be held liable for stuff their users posts helps prevent this issue.

There's no circumstance here where twitter is being attempted to be made liable for their users posts, so what relevance is 230?

Musk is mad that advertisers don't like being seen next to posts calling for violence, and are using their first amendment right of free association to NOT associate with a platform with a lot of calls to violence.

If you return to the “any effort to moderate lawful content at all gives you publisher-style liability over the whole service” rule that existed pre-230, you destroy all commercial UGC sites pretty quickly. Because flawless moderation at scale isn't possible, and the market for unmoderated sites is pretty limited. (Especially because either way you have to respond to reports of certain potentially unlawful content to avoid criminal liability, and that rule creates a huge risk that a slight error in that response suddenly opens you up to unlimited civil liability for other content.)

We know this because that was the emerging situation that Section 230 was the response to.