They usually send you a 'pre-print' which (in their opinion - I'm not a lawyer) is not subject to the same copyright as the final reversion which was sent to review.
Thanks. Any sources for their opinion? Probably I shd read the copyright release form in more detail, but if you think terms of copyright this won't fly.
“Authors publishing via subscription models may also self-archive a copy of the accepted version of their manuscript (post-peer review, but prior to copy-editing and typesetting) in an institutional or subject repository, where it can be made openly accessible after an embargo period, in accordance with the relevant Springer Nature self-archiving policy (Nature, Springer, or Palgrave Macmillan)”
- via their non-commercial personal homepage or blog
- by updating a preprint in arXiv or RePEc with the accepted manuscript
- via their research institute or institutional repository for internal institutional uses or as part of an invitation-only research collaboration work-group
- directly by providing copies to their students or to research collaborators for their personal use
- for private scholarly sharing as part of an invitation-only work group on commercial sites with which Elsevier has an agreement
After the embargo period
- via non-commercial hosting platforms such as their institutional repository
- via commercial sites with which Elsevier has an agreement“*
(Seems a bit less constrained than SpringerNature)
Even if it is potentially technically illegal, I don't know about anyone who tried to stop it. Note that some release forms explicitly allow author's versions of the covered work for download on the author's website. There's usually a stipulation that they need to be different in some way, for example by not using the same formatting template as the journal/conference version of the paper.
I don't see any new insights on the page that you linked. I personally signed copyright transfer forms that allowed for author's versions. There were some conditions that I don't remember in detail. But the gist is that a commercial publisher still allowed me to have a version of the article text online.
They make you go through hoops and remember you - after a few requests the paywall emerges.
In this modern day, with publishing costs steadily falling, their demands for payment have become ever more demanding