I think he's more interested in the power of twitter as the public square. There's no doubt Trump won his presidency through that social media presence (and his non-stop rallying of course). That kind of power is more useful than say buying the Washington Post.

I would be more interested in him implementing certain features like a journalistic credibility score for outlets and individuals. Base it on number of retractions, mistakes, and outright lies. Surely a score like that might put certain fake news propagators in line.

This is something he pitched before although as a standalone website. Integrating into twitter seems more useful.