If there is no definition/agreement of what wrist snap is, you can't argue whether it is or isn't a real phenomenon. You said that modern strokes have wrist action - why can't we call this "wrist snap"?. The cocked wrist position involved with wrist snap is not actually laid back, the muscles in the forearm are used for this to happen disregarding forward wrist action.
Wilson ProStaff 6.0 85 - bab. vs nat gut 17 M55 C53