To me it seems like someone was given the 2002 transfer and tasked with making it look "better" for BD but given very little time and budget to do it, so they just ran it through an automated cleanup, which got rid of the excessive grain of the 2002 transfer and some of the dirt but it of course made the transfer look even fuzzier, so they added edge enhancement on top and then just did an aspect ratio correction and a few corrections to the colors, where fans pointed out errors on DVD (kind of like Luke's green saber was fixed for the SW BD).