All Kishimoto did was draw the covers, he had no involvement with the story line nor approved them. Someone once posted a timeline *created by Shueisha* apparently denoting it as canon, but I read it and nothing mentioned Kishimoto or it being canon at all. All it did was shove the novels into a timeline. People speculated that was enough but it's not, because any and every filler fits somewhere in the timeline.
Nor did he edit the novels. Some people, especially on Naruto Reddit, made a lot of unfounded speculation. Chapter 700 wrote off the novels as a gaiden. A gaiden in Japanese is a side story not considered official. Not to be confused with "Naruto Gaiden" though, where gaiden there means chronicles.