University Publishing/Initiatives for OE contributions/Conflict of Interest?

I am wondering if there is a clear outline of the expectations for higher ed institutions to contribute research to open access. I am a little behind on what policies are in what places- being American, obviously I am ego-centric and only have any awareness of what is happening here… (sort of kidding). But last I recalled, there seemed to be serious discussions about making faculty seeking tenure to make a certain portion of their articles OA… Are there institutions that have done this? And then I am wondering about the institutions in the United States that have been supportive of OE from the earliest stages- particularly MIT. But both MIT and the American Library Association still have their own publishing, and the books are quite expensive. I am trying to wrap my head around how it is possible to still publish expensive materials but at the same time have institutional support of OERs? I feel like I am missing something obvious, and it is kind of like working on a puzzle and not having some key pieces. Anyone who can help shed light on this or point me to articles that explain it better, it would be greatly appreciated!