Who would have ultimately paid for the scan and who could have requested it? It’s assumed that Disney made the request. Can this also be that they would not have done so for somebody (like you or me) who doesn’t own the copyright to the film?
Since Disney owns the films I think they can request a scan whenever they want. I believe the user who posted the information when he said that Disney requested the scan to be done, as he has shown himself to be honest and trustworthy when it comes to things like this over the years. I’m not sure how exactly the Library works, but I guarantee that they would not make a scan of a film simply at the request of someone interested in viewing it. Disney has a lot of power and influence and surely can get whatever they want.