Your description of Minimum Viable Product appears to classify the MVP as the end-point of the process. My thinking is that the MVP is the starting point of an iterative development process. Its value is that it allows users to participate in the product design, and from this feedback you can modify and extend the initial product with the things they actually want rather than the things you imagine they want. The MVP is the first question you ask your users "Is this what you want?". Users find it very difficult to engage with design documents or specifications, but put a product in front of them and they will understand you and tell you what they want different.