canon is such a media illiterate concept tbh. like it asks the question of "what is real within the world of xyz" but well, nothing is, because the world doesn't exist. none of it is real. and apart from that, who gets to decide what's real? so you're saying that if the author of a book says on twitter that smth is real within its "canon" then that's true, and if they commission someone to write a 2nd volume to it then that's also canon even tho they didn't even make that up themselves, but if a third person makes an unlicensed 3rd installment then that isn't canon? so you're not only basing your understanding and interpretation of prosaic art on some perceived made-up universal truth about what happens beyond what the work you're reading explicitely tells you, but you're also letting the people who own the legal rights to said work (and ONLY them) decide what said universal truth is??
"any book's meaning, implications, content and correct interpretation (which totally exists btw) is determined by what the owners of its IP say it is. the book itself only has a say in this if its IP owners don't say smth contradicting. and another book that was only perceived and made after the original book was already finished can also change the meaning of a book, but only if it was officially licensed by the IP owners; otherwise it is of no cultural relevance for any interpretation of the original book and is in fact misinformation (even tho both original media and fanfiction are both equally made-up)" is literally a bootlicker mindset towards the corporations that seek to monopolize storytelling and creativity
humans have always told tales and built upon other ppl's tales until they become collective myths for the enjoyment of both storytellers and listeners, and that's an important part of culture i think, and now whenever a tale is successfull corporations "buy the rights to it" so they can decide which storytellers additions to the myth are "truth" and which are "lies", and most people (incl leftists) question neither whether this made-up true-false-binary in regards to collective myths is real nor whether we should rlly let whoever has the most money define it