Painting out these movie mistakes as part of a restoration is wrong. What's in the movie is in the movie, and altering the movie to this extent is a form of revisionist history. Cinema is worse off when over-aggressive restorations alter the action within the frame. To me, this is equivalent to swapping out an actor's performance with a different take, or changing the music score during an action sequence, or replacing a puppet creature with a computer graphics version of the same creature decades after release. Movies are a moment in time. But I digress.
I disagree strongly with this comparison. Yes, having a verion that is accurate to the theatrical release available is an important part of movie history. But director's and other alternate cuts can be superior to the theatrical release and fixing special effects or errors on post to remove distractions on older movies is comparable to digitally editing them out before release for a modern movie. Cleaning up potentially distracting mistakes is not in any way comparable to changing a performance.
Adding new stuff like having Greedo shoot is comparable, because it changes characters. Digitally fixing a license plate falling off during a take is not.