Its a promise about the future. Read the last paragraph:
>The future use of these features without supervision is dependent on achieving reliability far in excess of human drivers as demonstrated by billions of miles of experience, as well as regulatory approval, which may take longer in some jurisdictions. As these self-driving capabilities are introduced, your car will be continuously upgraded through over-the-air software updates."
Beside, from the video, I don't see the need to be "hyper-vigilant", yes you do need to pay attention, which is recommend by tesla, but far from being hyper-vigilant.