Im surprised there aren't student clubs or something hosting instances now that you mention it. That would be a great student project for any CS or even journalism schools.

Depends on the university. Some of them are still like that, some of them are totally ideologically captured such that they have encoded being anti-free speech into their conduct codes, and/or they simple would not want to deal with the fallout of bad actors would/could do to their servers.

A lot of university's slide towards authoritarian centralizing of power post COVID along with internalizing their student bodies. Sadly. They themselves aren't the bastions of freedom and truth they once were, because those things don't make the bottom line go up. Many also closed off spaces and programs that were previous open to the public to further isolate themselves from the rest of the world. MIT had libraries and other facilities anyone could use, and now they shut them all off from public access post COVID.