EU is just that EU.
Noone , even Steve Perry the author of Prey , thinks Eu is canon. Even there is a problem with EU i.e. it goes against something established in the films then the film wins.
Eu isn't canon. Thats like saying filler characters in anime that aren't in the Manga are real. They didn't come from the original source.
Next Fan Fiction published by Dark Horse will be canon if we go by your logic!