Canon is what actually, factually happens in the show. There can be some ambiguity to the meaning of things that are canon. However, “but it’s canon for so many viewers!!!”? No, that would be a headcanon about canon, which is a type of fanon. Which used to mean something that was not factually contradicted by the canon, but these days seems to be anything someone has decided to want to believe is true, even when it does contradict the canon directly. I’m sorry that understanding words have actual meanings is hard for you, but stop trying to make that everyone else’s fucking problem.
Also, if I never see ‘Dean has obviously been consistently lying about his sexuality for X years because reasons, lulz!’ ever again, it will still be too goddamn soon.