When I first got Dragon Ball in the early 2000 the ‘back’ (regular front) would have instructions on how to read it correctly. I could definitely see this being true.
Given that about half of Amazon's "reviews" are basically "I didn't read anything and ordered the wrong thing. 1 star." I wouldn't expect it to be a joke.
I dunno, I've seen certain publishers of manga in English put big warning pages on the back (or what people might assume is the front) saying things like "Hey, you're starting on the wrong side!" Those warnings are there for a reason.