At a number of points, this steps squarely into a decades-long debate in literary studies about the nature of reading and of interpretation. This is a debate that is still - perhaps permanently -unsettled. However the view Wikipedia is taking - that there is some core of knowledge that is "descriptive" as opposed to "interpretive" - is decades out of the realm of accepted. It's a discredited view.
Could you explain the nature of this debate? While there is certainly a grey area between "descriptive" and "interpretive" I think the basic plot elements of a novel aren't generally open to interpretation (there will be exceptions for certain parts of certain novels, and those can be dealt with on a case-by-case basis).
Also, it's important to note that novels were just an example - in most cases, there isn't even a significant grey area, eg. you can use someone's birth certificate as a reference for their date of birth, you cannot use it as a reference for them having been born during the Great Depression and thus having had a tough childhood. The former is a simple fact, the latter is a (somewhat speculative) interpretation of that fact.