AMP for email in GMail can be turned off and is off-by-default if image-loading is turned off.
Where will we see the setting, and is it still rolling out? I can see in my old Gmail account where I have "Ask before displaying external images" selected, so I'm presumably protected from AMP for now, but I would've expected to see the setting for AMP alongside it.
If the statement was, "I think AMP for Email is perfectly fine as is and doesn't need an option to disable." that might be something to call for disclosure.
To their credit, the Google Cloud product team does this religiously.
(toomuchtodo is indeed accurate that the Google Cloud team are top notch on disclosures.)