I've seen the cycle too many times over the past decade or so. It's really bad with the various desktop UI frameworks, but it happens with most everything they put out. If something doesn't get immediate traction, and doesn't have strong champions inside of Microsoft, things all too often wither on the vine and go by the board. Big bang initial rollout coinciding with Build, showing off some fancy capabilities that never quite actually are realized in the version released to general availability.