I think a lot of people here aren't looking at this in the right way:
They don't have to accept accounts for student or let students interact. This can be an alternative system for disseminating announcements with optional mechanisms for feedback. All they need to do is federate and then any of their students subscribe.
I've been wishing that my my governments (at all levels) would do this so I can get notified of things like changes to bus schedules or closures of highways and shit.