I have not seen any government adopt such a standard.
some EU countries claim to provide anonymous age verification services, but those only hide your identity from the relying party. the site you visited is logged to the government's database along with your identity, before you're redirected to the target site with an "anonymous" token.
> the site you visited is logged to the government's database along with your identity
Is that true, or are you spreading FUD? Because the system in question is not even live yet, it's only had experimental releases.