That extra chrome didn't even include a way to see the original URL until after much squealing. It did, however, include left/right swipe to other people's content. The MVP that rolled out fairly clearly shows who benefits.

An edge cache of an optimized page is plenty fast without preload. Images, in fact, can be preloaded cross domain if that is really needed.

You know it's a mess when the New York Times has to inject a "sorry this video doesn't work on AMP pages, visit our site" message on stories.