Absolutely, but that's a framing device/motivational aspect, rather than the mechanics of the actual learning. "Here's what we're aiming for, and here's why it

Absolutely, but that's a framing device/motivational aspect, rather than the mechanics of the actual learning. "Here's what we're aiming for, and here's why it matters" should be the introduction, setting the scene and establishing the flow, but then you introduce the various blocks-that-will-be-built and start working up to them in the stepped fashion.