What's the difference between soup meat and stew meat?
Stew meat is usually a piece of meat that is tough when cooked quickly, but becomes tender over a longer cooking period.  Examples, Beef - Brisket, Cheek, Chuck Steak; Pork - Brisket, Shoulder (aka Butt).

Soup Meat can be a flavoursome cut which is between the quick and slow cook cuts to give flavour and remain a good eating texture.  Example, Chicken - Thigh.