FDA changed standards for chocolate several years ago at the behest of Hershey's and other commodity chocolate manufacturers. Previously FDA required some amount of cocoa butter in the chocolate. The current standards are :
"Milk Chocolate
Milk chocolate is the most popular type of chocolate in the United States. To be marketed as milk chocolate, a product must contain at least 10 percent chocolate liquor, at least 3.39 percent milkfat, and at least 12 percent milk solids."
www registrarcorp com fda-chocolate-standard-identity/
While i never particularly liked Hershey's chocolate prior to the change, after it turned into a total waste of money and calories.