I don’t think it’s true that he expected it to be seen as silver-gelatine prints
I'm sure he expected to see prints, but they weren't particularly precious at the time. The value of his photography was publication - either in magazines or in books. No one was paying anything significant for any individual prints.
@nikos79 - if you don't find any significant difference between seeing a print and seeing a photo on a screen, that's fine. You'll likely never convince anyone that's made prints that that is true. From the very first time you start to try to make a good photographic print, you begin to realize just how easy it is to make a bad print from the same negative. The skill is being better able to realize in the print the possibilities in the negative - and to do that, you need to know the material you're using.
While it is true that there is skill involved in digital editing of scans (or digital photos), you have no control over what screens display your photo. You get more control if the photo is printed. But if you know anything about professional printing of art images, you'll know that each print calibration gets approved by the photographer (and prints that need recalibration of the print process get destroyed). So clearly there is an ideal the artist is trying to get realized in that process as well - which means it's easy to get bad prints and more difficult to get a good one.
Essentially, this is about subtle characteristics. The composition of the photo is the same across the options: image on screen, bad print, good print. So, yes, you can see the photo and think "That's a great photo" in all those instances. However, only one thing allows you to say "That's a great print." Is there an equivalent for a photo on a screen?