Question: Why didn't the aunts just tell Miguel that Ernesto De La Cruz wasn't his grandfather when Miguel was rambling about it when he entered the Land of the Dead?
Greg Dwyer
24th Jan 2018
Coco (2017)
Answer: Because Miguel didn't unambiguously talk about his wrong assumption. In other words, he never said, "my grand-grandfather and Imelda's husband, Ernesto de la Cruz" (which is wrong). He only called him grand-grandfather and Imelda simply referred to him as a good-for-nothing musician. The aunts, uncles and the grandfather Julio all knew about Hector, as can be inferred from the reunion scene.
Answer: The aunts may not actually know. Because his ancestor hated him so much, she may have talked about him very little in both the real world and the afterlife.
Greg Dwyer