Interesting! I guess everyone has different opinions on what is optimal.
Well to remove matte lines and such would be remastering, because you are taking those elements and recombining them in a way that is not what was originally done.
Matte lines are a result of the process used to create the film, so they should be kept.
Things like channel misalignment come from the process of creating prints from the already finished film, so fixing them is the correct move if your goal is to get back to what was on the negative.