They are not freshly remastered (i.e. for the purpose of this release) - the Japanese remasters used are from 2011/2012 or thereabouts, but were never employed outside Japan until now. But they are not the original Rhino remasters that were, say, contained in this 5er box a few years ago:
I have that too and listened side by side, no comparison, the old stuff was a murky and incredibly flat affair. And while Bob Ezrin's wall of sound productions have the habit of sounding a little indirect, the new(ish) remasters are much more there. At this point, the best quality of old Alice Cooper (Band) recordings you can get.