The problem is that what is and isn’t canon is decided by the devs.
They can go “Actually Uther was a Pink-Haired Gnome Woman with a pet kookaburra and everything we see in WC3 is the Jailer twisting our recollection of the past because reasons” and that’s technically canon now
It’d be incredibly stupid and another example of them trying to take a dump on old lore, but it’d technically be canon.
So when new canon conflicts with old canon, they just go “NUH-UH” like a kid getting called out in breaking the rules in the game he made.