Many Universities already have their own dedicated subreddits that are usually moderated by a mix of faculty, staff, and students. I know of at least one sub moderated in part by the chair oftheh math department, who is as funny as they are savage.

An above-average level of shitposting goes on, sure, but it's also a great venue for the school's online community to engage across organizational boundaries.

But people can still reply to posts so you'd need moderation still.