As far as I know, that's only part of the triple task of most museums, which is to disclose, preserve and foster research.
I agree. I was contrasting it with the goal of the collector - who tends not to care about any of those things. And, at any rate, with a straightforward colour photo, a new print that is of the same quality and character as the original (when it was originally made) performs all those tasks. The question remains, though: are these newly printed prints of the same quality and character as the original?
I would find it more plausible if museums would accept a new version of the work for exhibition purposes while retaining the original copy in safe storage.
I agree with that, also. If the point is to have a copy for display, then the original should be reserved in storage. They would then need to pay the cost for a new print, though, since they would not be relinquishing the old one.