The biggest takeaway, looking past the headline: “This week a federal appeals court, ruling in a case brought by conservative activists against social media companies, affirmed that private websites are not public spaces and social media companies don't have First Amendment obligations. Any truly strong limits to Section 230 would almost certainly require action by Congress.”
Its an interesting thought experiment to assess in what ways Twitter is a "private website". It really is a public web space that is operated by a private company, but I can't help but feel that the nuances and similarities of what Twitter really is and what responsibility they truly hold in society is above the courts comprehension.
One way of looking at it is that the internet is the public space, and twitter is a very large private building in that space. Trump can start his own blog any time he wants, hosted on his own site, and be in the unrestricted public space.