Agreed. I'm surprised you have not seen this before, though. This is pretty much how most of the orgs I've been part of have operated. Product owns the "what", and engineering owns the "how" and "when". If "when" becomes immovable due to externalities, "what" is negotiated. Some times, eager engineers will say yes to "what" and "when" , and "how" suffers (quality). Some times product defines "what" so badly, both "how" and "when" suffer.