It seems like there are a few distinct kinds of questions here.
You are trying to estimate the EV of a document.
Here you want to understand the expected and actual interpretation of the document. The intention only matters to how it effects the interpretations.
You are trying to understand the document.
Example: You're reading a book on probability to understand probability.
Here the main thing to understand is probably the author intent. Understanding the interpretations and misinterpretations of others is mainly useful so that you can understand the intent better.
You are trying to decide if you (or someone else) should read the work of an author.
Here you would ideally understand the correctness of the interpretations of the document, rather than that of the intention. Why? Because you will also be interpreting it, and are likely somewhere in the range of people who have interpreted it. For example, if you are told, "This book is apparently pretty interesting, but every single person who has attempted to read it, besides one, apparently couldn't get anywhere with it after spending many months trying", or worse, "This author is actually quite clever, but the vast majority of people who read their work misunderstand it in profound ways", you should probably not make an attempt; unless you are highly confident that you are much better than the mentioned readers.