I really don't understand your comment, and all subsequent responses along the same line. The digitized van Gogh paintings are perfect copies of the original public domain works. For the US, Bridgeman Art Library v. Corel Corp. [1] makes it perfectly clear that the images are not protected by copyright, and there is similar law and legislation in Europe.

What do you mean with the ability of the museums to choose a license for the paintings, and what is the "sub-A4" license you refer to?

[1] https://en.wikipedia.org/wiki/Bridgeman_Art_Library_v._Corel....