You can expect that he knows some key details that will appear in the guide, but for much of the story he's filling in the gaps like we are. But he's rather good at filling in the gaps, so there are two good reasons to listen to his thoughts.
Until the guide comes out and they two can be contrasted the ambiguity about the "officialness" of his opinion just muddies the water for me (Leaving aside the validity of authorial intent vs audience interpretation of course)