If you don’t care about directly making money, you can treat the platform as a way to promote or reject whatever messaging you want to millions of users.
If it’s a public company, it’d be subject to the will of the shareholders and have other corporate responsibilities. If it’s private, it can do whatever he wants it.
There is nothing that says a public company must only be motivated by growth. Tesla's mission statement doesn't say anything of the sort and has done things that don't fulfill the idea of growth or profit at all costs.
Now you might argue that institutional investors don't care about that since there's an indirection between actual shareholders, but that's a related but different issue.
Also I bet they would call to regulate or even nationalize social media platforms as soon as companies like Twitter switch to a more balanced moderation approach and don't aid in amplifying certain politics.
If he does, there will be a significant share premium paid to current holders from the acquirer.