I don't dispute that fact or supposition. My point is this debate which I started about who has the exclusive agreements clouds the issue of DRM. Even if Adobe doesn't have exclusive use contracts does not mean they can't do this in the future. Also changing to ePub doesn't mean this is the end of the DRM changes. Something in the future will appear and we will again lose our libraries to the new DRM.
I wrote an email to customer service on the Mobipocket site. The Amazon response asked if I was satisfied with the answer. I click the link to say no I was not. I sent another response to that link. Remember Jeff Bezos apologized for deleting the Orwell eBook and offered compensation. If everyone here wrote a strong but respectful message to Amazon then they just might wake up. They do respond to their customers but at the moment we have been silent. Speak up!!!!
Of course if the agreements are secret then we really don't know if the Adobe / iRex agreement is boilerplate or something more exclusive with Adobe.