from the upload rules - The uploaded image should be the best representation of the actual final print and nothing more. We still accept neg scans in the galleries. We accept that some adjustment of contrast, brightness and sharpness may be needed to match the physical print and, for negative scans, to approximate a straight print.
In the past, that last sentence has been said to mean that you can scan a negative and make it look like the analog print you've already made and that's ok to upload. I do know that frequently it's easier to scan a neg and make it match the print than it is to scan a large or curled fiber print (which don't always scan accurately if toned or on warm paper). I honestly don't remember if I've uploaded any this way, but I know I have some that I've never printed smaller than 11x14 and it would be much easier to scan the neg than to stitch scans of the print.