anime only material is referenced in the novels multiple times, kubo supervises the anime, bounts where supposed to be in the manga, kubo has said if it doesnt fit into the story hell remove it.
Idk what kind of argument that is, yes the movie is about tosh, kubo makes a tie in chapter + advertises + works on it + makes a guide, interview, and comic for it + a different perspective directly means the same
Yes it would, it connects more than movie 1 which is referenced in the manga.
and he made the plot.
If that’s the case then the novels + upcoming anime should not be considered cannon. Kubo can work on it makes the plot, have tie ins, advertise, and say they’re the same and it’s not cannon still