I've always leaned towards marketing gimmick. Mercury Nashville did a re-release of a Hank Williams gospel album with the line "original recordings remastered." All of the songs were from another release a few years back. I asked the question on Amazon were they not remastered already? Loljimmyjet said:those "recorded by the original artists" never sound as good
cuz the artist does not have the same singing talent as he did when he was younger
i thought we were talking about the original recording, re-mastered
i still dont know what studios mean by "re-mastered"
i always just thought it was a sales gimick ?
but perhaps there was some noise/hisses that were removed, to make it sound better ?