Board Thread:Naruto Discussions/@comment-25691159-20200529162803/@comment-25691159-20200531165159

Because it would be a statement to hype it up? Kishimoto has a habit of info dumping character abilities midfight and there is little reason in exclude that statement, considering how many characters were actually discussing the Amaterasu throughout the manga.

Kishi never wrote any of the databooks afaik, that was one of his assistants. No mangaka actually writes supplementary materials like guidebooks from my knowledge.

Because they finished burning their target? Even with seven days it would probably be enough to burn down an entire country. You are also excluding the plot factor from this.

The databook itself had incomplete information/info that was changed later in the manga and is not a gospel, the manga is.