Board Thread:General Discussion/@comment-38027640-20190412014110/@comment-957629-20190424151828

You say that Brave Souls proves the Canon and yet in Brave Souls, those characters and story characters are listed as "Alternate" or "Side Stories" with the other filler and not alongside the Canon story mode. So this is not proof that these novels are any more canon than the previous bunch. Kubo can say whatever he wants but until he's writing it we do not consider it Canon and clearly neither do the creators of the Game you just tried to use as proof.

EDIT: The only thing any of this is proof of is that, like most people, they like making money. The novels are current so the Games add them in.