I respectfully disagree.

Even if the original master was shot in 6k, after going through a traditional Intermediate Positive, then to IN to release print stage in the lab, it wouldn’t go above 2K. Plus the weave and lack of pin-registration in most projectors, plus the less-than-optimum focus, you could easily wind up with well below 1080 resolution.

Furthermore, considering that the master was digitally shot at only 1,5k, there is really nothing to get at 4k, but dust and film grain.