[gregable]

AMP hides the entire page to avoid what is known as a Flash of Unstyled Content (FOUC). The document unhides as soon as a single AMP javascript resource loads, or an 8s timeout if that fails. That javascript is very cacheable and is often already in the browser cache to begin with.

[the8472]

The page is also readable without that script and browser engines already delay the initial paint. So this is entirely unnecessary.