I have a theory about this and maybe Ken can confirm or deny it:
The shrinkwrap style shown on vintage-sierra is most likely the way they were wrapped at the factory. (First Editions) Usually, there would be cards and/or offers inside the box that were dated materials. Possibly, Sierra sent out a memo to software retailers saying, ‘Hey, there’s an AdLib coupon in your SQ3 boxes that’s going to expire. Please remove it.’ and hence, the re-wrapping.
Anything that has the ‘Value Priced Merchandise’ sticker is also a re-wrap.
-Tom.