1. Musk is going to discover (and maybe admit?) that fixing Twitter is harder than he thought. It will be just like self-driving, which seems straightforward, but which actually has thousands of edge cases which are hard to solve with a single general system. Nevertheless, he will persist, because that's what he does.
2. Current Twitter makes a profit on advertising, which means Twitter needs to encourage high levels of engagement, which means they need controversial (emotional) content, but not so emotional (toxic) as to drive people away. They need to be as close to the line as possible, which is why they spend so much effort on moderation. Musk's solution is, I predict, to try different revenue sources so that engagement with the feed is not the primary metric.
3. Musk has already stated that his goal is the Everything App (which he calls X). The Everything App has news, social media, games, videos, and a payment infrastructure (both to pay for content and to get paid). He wants Twitter to replace Facebook, Instagram, Google News, YouTube, Twitch and PayPal, etc. Will he be able to pull it off? I expect he will deliver the 20% of those services that are high-value, but pitch it as a complete solution. That might actually be good enough for most people.
4. If he accomplishes #3, then the revenue source is obviously: they will take a cut out of every transaction going on in the network. Maybe ads are a component, but they don't have to be a major component. If engagement is no longer the most important metric, then it's possible to allow every person to have a radically personalized feed. Even something as simple as only showing you tweets from people you follow (what a concept!) would revolutionize the experience and drastically reduce the need for moderation.
5. Since Twitter is private, Musk can front-load #4 even before the Everything App is ready. If he hasn't already burned the current team, he can make the experience better relatively quickly and worry about profit later.
6. Now for my safest prediction: No matter what he does, some people will hate him for it.