They could have just wrapped the fancy cover loosely, allowing a reader to unfold it, but then placed a separate transparent non-adhesive, slip-on cover on top of it all. I have seen such covers, though I have no idea if the ones I saw came with the books or if someone bought them later, separately. In any case, you can buy them. Sure, they might not last forever if readers get interested in what's below and treat them roughly. But it's an option. Pros like library workers should be aware of them. Even if libararies had rejected the idea years ago for their own reasons, it would have been good writing to mention it in the chapter, as the audience might not be aware of the reason libraries wouldn't use them.