I knew about the degrees of canon. What I didn't know is that newer source replaces the older ones. That's completely insane and lacks logic in my point of view... but it clarifies a lot.
Still I don't have to care about canon or not if different pieces fit with together and the story makes sense for me
And even if the 'Jedi dude's' story it new canon from now on, I still think it isn't some kind of revealed truth about Revan but only his point of view and his approach to Revan's fall.