What is сanon? Some kind of church teaching?
A films are artistic works. Sometimes they have a continuation, sometimes they don't. Sometimes the story is rewritten and changed from scratch, sometimes - from a certain moment. You can look at the whole work, and sometimes only at a part. You can admire the whole work, and sometimes only part. Sometimes you need to delete and rewrite the unlucky and ugly piece of work.
Enjoy, watch and analyze each film individually or in combination with others. But do not think that the story you are watching is as dead as the unnatural dogmas. And if someone announces a reboot or a retcon, we must accept it as another piece of art. Instead of splashing saliva and yelling in a fit of rage: "NOOOO, THIS IS A DANGER FOR CANON! THIS IS HERESY! WE MUST PROTECT CANON! THE STORY SHOULD NOT BE REWRITED!".
But I understand why people love and defend the canon - it allows the brain to be lazy and proud at the same time. People defend the canon as an unchanging set of rules and guidelines, not realizing that at the will of the studio, everything can change easily and quickly.
So, fk the canon.
And, if canon is a kind of church teaching, then headcanon is is a sect.
So, fk the headcanon too.