They can't force you do anything, but a book or a piece of music etc, is often designed in a particular order so you get a particular effect.

You don't look up the end of a whodunnit before reading the beginning because that would make it kind of pointless.

And yet, some people enjoy doing that. I have no idea why but I think they should be allowed to do it.

In any case, Amazon claims this is spoiler-free, which would be easy to implement by feeding only the portion you've read into the LLM context.