It is illegal to sell canned fruit as fruit cocktail unless it has a certain percentage of pears, pineapple, peach, grapes, and cherries. If it is missing any of them or has a disproportionate percentage, it is illegal to sell it as fruit cocktail. That is why the kind you see with extra cherries will not be called fruit cocktail.
PDF containing the US gov's fruit cocktail regulation.
PDF containing the US gov's fruit cocktail regulation.