People read far too much into the word "canon." Even canon itself is not exempt from being overwritten or contradicted by later canon. Heck, the Special Editions of the original trilogy should prove that, not to mention the reinterpretations that the prequels introduced. And we've seen canon retconned or ignored in most other long-running franchises. Modern Star Trek
has ignored some of the sexist assumptions of the original, or ignored some of the more implausible ideas of bad installments like "The Alternative Factor," ST V, and "Threshold." Marvel Comics constantly rewrites its history to fit a sliding timescale, so that stories that originally happened in the '60s or '70s are now assumed to have happened in the 2000s. Dallas
retconned a whole season to be just a dream. And so forth. Canon has never been a guarantee of permanence.