I’m not sure. As far as I know, I’m not aware of any other masterings for each album other than what each one released with. Unless we’re talking about that anniversary compilation from 2015, which that would be strange because only a few select tracks were remastered from each album. Same thing with the singles though, unless the singles had alternate mixes, it’s probably just the single mix right? Which is why the wording on “recent remastering CD” isn’t clear to me.
Without a remaster, this particular set just doesn’t seem like it’s adding much value. Longtime fans probably already have all the albums and new fans are (probably) not gonna spend nearly $300 to try the band out. So maybe at most you get a nice new photo book and a collection of PVs.