There was a camera registration issue in the scene with the tarantulas at the beginning of Raiders that caused the image to drift in and out of focus. I guess they didn't consider it bad enough to reshoot, but it was always visible.
This one mentions DNR, but says it's not excessive.
https://www.homecinemachoice.com/content/indiana-jones-4-movie-collection-4k-ultra-hd-blu-ray-review
The discs have HDR, so by definition they have been regarded and remastered, though how different they look from the blu-rays of course remains to be seen.
If the films have been remastered, they may offer new blu-ray versions from the new masters some time down the road. That's what's happening with Mission Impossible and Tomb Raider.