Arguably this means that Google is breaking point 11 of their own AMP Cache Guidelines [1]. If I ran any AMP pages, I would be quite upset.
1: https://github.com/ampproject/amphtml/blob/master/spec/amp-c...
1: https://github.com/ampproject/amphtml/blob/master/spec/amp-c...
We need more pushback against Google doing stuff like this, even when at first glance what they push for seems "positive."
No obstruction of the contents, branding or attribution of the original AMP document.