His character could become more closed - off. Losing Peter, who was such an important part of his life, might make Yondu build higher walls around himself to avoid getting hurt again.
Death in novels is sometimes a tool for character development. When a character experiences the death of a loved one, it can change their personality completely. In 'A Tale of Two Cities', Sydney Carton's sacrifice, which is a form of death, shows his ultimate transformation from a rather aimless and self - loathing man to a hero. It also reflects the social unrest and the cost of revolution at that time.