Did Adobe ever create install discs that didn't have cdkeys?

I'm trying to get a hold of an older Adobe Illustrator CS6 version. I found people on ebay selling, what they claim is a "legit" copy, but claim that the product doesn't ship with any cdkey and that it "auto" works. This seems fishy to me, because of how much I know Adobe loves their cdkeys on pre-cloud products.

Can anybody confirm if Adobe ever created Adobe Illustrator install discs that never included cdkeys and that performed the licensing or owner verification using some other method?

(I had a previous key from years ago, so I thought I was covered having a CS6 version and could still install Illustrator CS6, but when I recently went to reinstall, it said my current key had been revoked, even though at the time it was purchased, it worked fine.)

I'm looking for options to still use a CS6 version. This somewhat "fishy" seller was the most legit looking seller I could find.

Any help on this matter, would be greatly appreciated. Thanks!