In this modern society, there are many adults who have never so much as seen a dead body (having never even gone to wakes). In previous generations, and in different societies, seeing dead bodies is common place and does not have the same power to disturb. Does it harm a child to desensitize them to the sight of a dead human body? I don't think so. Does it help? Probably. It opens them up to being able to experience a wider range things, even if it is just going to somebodies wake, being able to watch that optional-attendance autopsy video in highschool, or consider becoming a doctor.
Further, in particularly prudish societies people may not be desensitized to exposed human flesh. Is an Amish child going to be damaged by the sight of a bare ankle? Is an American child going to be damaged by the sight of a finnish sauna? I sincerely doubt it. On the other hand, which is going to have a more difficult time wearing speedos when they join the swim team?
Many humans in industrialized societies are unaccustomed to the sight of an animal being slaughtered and butchered. Are children that grow up in farming communities where they are desensitized to this somehow at a disadvantage when compared to children who grow up in urban communities and only know meat as "that stuff that comes from the store"?