That there's no such thing as canon scenarios, when the player is deliberately given different choices? I'm absolutely serious.
Canons endings are only canon when the player isn't given any choice.... otherwise it wouldn't have been a choice to begin with.
Here's an example.
In "Knights of The Old Republic" you play a certain character. You get to pick between the male or female gender.
In a later, MMO-sequel to KOTOR, it is revealed that the character you played as in KOTOR was in fact male by canon, as determined by the writers.
There can't be two versions of the same outcome affecting every single player's game. A decision has to be made, and it is usually made to suit the needs of the story. In other words; picking the scenario that makes the most sense for the story moving forward. This decision is first given to the player, and they can accept it as THEIR canon, but there will always be a universal, era/universe canon determined by the writers or game/fiction makers. There has to be, in order for that story branch to be continued in a cohesive, sensible way.
OR, they can just avoid it and never address it.