A ways down in the discussion they note that there's really two parts to the proposal: showing the permission state and triggering the permission dialog, and se

A ways down in the discussion they note that there's really two parts to the proposal: showing the permission state and triggering the permission dialog, and separately having an in-content permission dialog. The article linked here doesn't seem to touch the second part at all. That's probably wise, and it doesn't mean the proposal is DoA.