I think it’s also worth remembering some people will want the best possible presentation of the Prequels, and even though the D+ versions aren’t as different - they’re still a better transfer than the 2011 blus, correct?
I believe they are the same.
According to thedigitalbits TPM is a new scan which was also used for the 3D re-release (there’s still a lot of DNR in an attempt to blend the film elements and digital scenes) and AOTC and ROTS are based on the old 2K masters (they were shot in 1080p but mastered in 2K) but with additional upscaling and “film look” processing to bring them to 4K. The grades are also slightly different.
The Blu-Rays included in the new set are downscales of the new 4K master, not the same as the old blu-rays.
I’d be curious to see a comparison.