Honestly....meat from the grocery store is tasteless long before it even gets to the store...JMHOInteresting that the "Modern Priscilla" book claims "fowl" has "long hairs" instead of pinfeathers. My young javas have lots of "long hairs." Also zillions of pinfeathers when molting. Think I'll stick with the Joy of Cooking definitions, which are generally consistent with the ones from Quebec. "Fowl" is an older hen.
I do the same as you with my chickens - make stock, then pull the meat off for use in other recipes. I'm amazed at how much flavor the meat still has after 3-4 hours in a stock pot. Meat from a grocery store chicken would be tasteless by then.