I don’t think Coco should get a sequel. There’s no more story to tell, as the movie wrapped up everything pretty well.
However, I could see it having a prequel.
Give me a movie focusing on Héctor when he was alive and how he met Imelda and how they got married and had Coco
Give me a movie focusing on Héctor’s struggles as he chooses to pursue music with his best friend, but every day he misses his family
Give me Living!Héctor content, you cowards