The re-issue of BAD cannot be compared to "Michael" which was labeled as a posthumous brand new album. The world mega star dies and an album comes out, it is sad, but his death contributed to the publicity of the sales, which is true for many artists when they die. So, they cannot be compared. Nonetheless, had there been no such controversy, "Michael" would have sold many more copies.
Many non-MJ fans bought it too, because of the star's death "hype".