...It also appears there will be a variation in packaging (an additional Delta symbol).
That intrigued me as well, it sounds like a full set will be replaced to us.
That's not how I interpreted it. I took it as the retail versions will be replaced, so if you're going out to purchase a set you can identify the corrected version.
It would be nice if we got a replacement set though, as that would mean that we would have both variation of the boxart and possibly more corrections (episodes not on the discs that contain audio errors). I find this unlikely though, as this would cost more to produce (3 discs vs 6 discs + packaging) and to ship in addition to possibly losing sales as people try to resell the original release with the errors.