The point is whether the publisher respects the authors right of republication of its own work, which is enshrined as inalienable right in [several jurisdictions](https://aisa.sp.unipi.it/attivita/diritto-di-ripubblicazione...) like the Netherlands. Even better, the publisher can avoid asking for exclusive rights, which are wholly superfluous for the operation of a journal.
It's worth noting that some (maybe even many) journal open access options do not allow the authors to keep copyright, even if they pay money! Open access ≠ keeping copyright.
> Copyright: © Cambridge University Press 2018
> This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
So I guess Cambridge is the copyright holder but it's available under CC, which I think qualifies as "generous reuse rights," as originally stipulated.
I would bet that MIT's choice to divorce from Els came from a combination of ideoligical, budget, and reputational concerns (e.g. the UC system divorced from them as well and MIT now stands in solidarity). So I don't think issue was likely to be decisive.
I think that if the price had been right, all parties would have found a way to argue that the stated terms had been met -- or to simply not address them.
So it's about the author being able to reuse it for himself, not about open access.
I've published a few papers (and have worked closely with Elsevier in a business context). When we published in a paywalled journal, we had the option of paying an APC [0] to make the particular article open access. So in that sense, we were not 'required' to relinquish copyright. It was just costly to retain it.
I suspect this is how some publishers argue that their contracts do not violate these maxims, because an APC option is fairly common, even at Elsevier, I think. Many journals also permit authors to post pre-edited versions of their papers on their personal websites.
I also think that, in line with what a commenter below, a large organization like MIT is not a coherent actor. There are political battles and compromises we don't see. So publishing this list could be someone's tactic for winning the internal struggle against negotiating with Elsevier.
Chris Bourg, who is a prominent advocate for open access at MIT, is my best bet for the driving force behind this:
https://twitter.com/mchris4duke/status/1271094535297339399
[0] https://en.wikipedia.org/wiki/Article_processing_charge