Aren’t they suing because of the 3d models??

No, they're not. The word "patent" is used in every single article about this repeatedly. Patents are not the same as copyrights.

A copyright protects a creative work: A work of fiction, a movie, a character.

A patent protects the method in which the way a thing functions: A machine, a chip, an algorithm, or in Nintendo's assertion certain vague gameplay concepts.