The photographer/porn studio probably has the originals if they bothered to preserve originals.
What
@ChrisD24 said.
If you are "improving" you are altering the source material. That's not how you respect the creator.
Upscaling can sometimes alter the original quality and aesthetic of an image or video, which may conflict with the intent of preserving its authentic look.
However, it can also enhance visibility and detail, making it a nuanced topic in preservation efforts.
The picture recently posted of Simon by the pool is a good example - it does look interesting, but his eyelashes look like falsies.
@patrickpenis even said "Eew, thats creepy." As you can see: it's not for everyone. I personally enjoyed seeing it but to me it's more like something made based on something else, and not the same piece in better quality.