In my time looking for published papers, I have only very rarely seen papers which are also hosted by the university of the author. I suspect in your case it was hosted because of something specific to the school or the author, rather than a general thing.

What I am seeing more often in my field is people posting a version of the paper on “arxiv”. This is a similar open-access approach, but you do have to be careful with arxiv papers as you can post anything on it, including work that never was or will be peer-reviewed.