simplex This is actually a super interesting theory. Trying out a laptop IPS panel that's decent so far, and one of the first things I notice (compared to the bad super-strainy prior one) is that it's so much easier to see the grain and textures that are actually "supposed to be" in an image.
For example one art illustration that I use as a wallpaper, I now notice that it's overlaid with a "comic book" style texture that I literally didn't notice before with the old panel, even though it's super obvious now.
Also some photo wallpapers that have natural chromatic abberation because of the camera that was used, that also seems more visible now instead of feeling like it's unnaturally smoothed out.
I've never thought of noise reduction before, but totally agree this is likely to be yet another one of the display "enhancements" that are messing with us lol