Earlier quoted context omitted.
Its possible it still fits the word. The bible is canonical too even though it's basically a pieces of disparate texts. Basically if it's the first and earliest record and the one that everyone looks to as the most accurate source it's canonical.
The whole idea of caring about "canon" is fundamentally bollocks anyway when it comes to stories
I know some people hate those franchises but like it or not, they are some of the biggest mythologies that came out in our time.