But the point is that the answer to "What is canon?" is that canon is something mutable and often self-contradictory, something that can be changed and reinterpreted by its own creators. It's not some simplistic seal of approval that you can stick on something to declare it "real" once and for all so that there's no further need to think or wonder. There's always going to be a need for the audience to evaluate and choose for themselves.
In other words, what is canon is every official screen production, but what is "real" within
the canon when it contradicts itself is up to the viewer's judgment. Canon is not the final, pre-emptive answer that many people want it to be.