So after reading the Rulebook, at the end of the credits on Page 7 there is an "action" that states to: "Read entry 9990 in the 'Dragonholt Village' book."

Upon reading that entry, it seems like an "end of the entire quest" type of thing rather than something that should be read before starting the campaign.

Why is this line written in the Rulebook?

From what I can tell without reading all the entries and spoiling everything, there might be more in the future for this game and they have already included story points that align with that in the village book. I've played through it twice now, first time not doing so hot at the end and second time getting the "hopeful ending". When I got the bad ending, it never told me to mark a story point, it just ended. When I got the good ending it said to mark story point "no spoilers" and move to the next entry which never referenced the story point I marked and then finishes with "this campaign is finished" I thought that must mean there is a future that requires that story point, because I can't find anywhere telling me to read further after the campaign ended. This reference at the end of the credits seems to read like it's in the future, as if eventually, after future material, you will be told to go back to Dragonholt Village and read the credits that will wrap up the whole game. So that to me feels like there are already future expansions for this great game in the works!