The 4K remaster isn't just an upscale....

There are small changes to the show.

The end credits have been streamlined and redone so the theme is the same for all episodes (the series finale is the only exception). Originally, there were a few episodes that had slight variations, such as a remixed version of the theme at the end of season 4 and extended versions used at the beginning of season 5. On the 4K remaster, the theme is theme same as all the other episodes in these instances.

The biggest modification is reframed shots. When the show was released in 16:9 on DVD, many fans caught mistakes like crew members/equipment occasionally showing up on the sides of the frame. For the remaster, these shots have been reframed to cut out these mistakes.

With all these intentional changes, it makes me less inclined to believe that the censored episode debacle was an oversight. But that's Shawn Ryan's official position on that particular subject.