> But as the alternatives get better, they would ideally migrate away to some solution that a) gives them more autonomy, b) let's all people contact them

The EU has already set up their own Mastodon Server [1] to do a) and maybe b)

[1] https://social.network.europa.eu/

I think there's a distinction to be made between using Twitter as one form of conveying information to some target audiences, and using Twitter as the primary or even sole form of conveying that information. The latter is extremely problematic, and I think is often what people are thinking of when they complain about political, public sector, and academic use of Twitter. It does seem unacceptable, for example, that some public service providers (transport, municipalities, etc) do actually use Twitter as the only practical way to receive up to date information on service changes and outages, and that many politicians now seem to use it as both their primary means of political communication and the first place they post official letters and actions.

Here, however, it just seems to have been another outreach mechanism for the university.

Before the musk acquisition you could not use it without being logging in. I heard that changed slightly but haven’t checked. But that sounds like a walled garden…