The entire idea of “canon” in fiction is quite frankly a little bit silly. It’s asking, what is “real” in fiction. Well the answer to that is simple, nothing is “real” in fiction.
Anyone can write a book of fiction filled with their opinions on how the story should go. Look at the Chronicles, one author’s opinion was that they were the be all end all truth of Azeroth and another person’s opinion was that it was just the Titan’s view.
We are playing a video game. The story is either in the video game or it is not in the video game.