"Canon" really only applies to things that have an officially stated or printed canon of some sort, and a lot of works of fiction, especially ones aimed at kids and families and don't really try to be particularly story or setting-driven do not have one. Mario is one such example.
Zelda...
The thing that bugs me about them recycling Bowser Jr.'s model for Baby Bowser is.... Baby Bowser has had 3D models before. One in Yoshi's Story, and another in Melee. The one in Melee in particular is clearly in the style of then-recent stock Mario character models, so I dunno what was stopping...