The straightforward implementation would be a mandate that every website over a certain size must publish tags about what types of content their site contains, the user-user communication features, the moderation policies, etc. These would be legally-binding assertions on the part of the site operators. Browsers would then allow setting parental controls based on these tags, or other criteria the parents choose (eg no social media, even if social media companies go out of their way to make sites their lawyers deem child-appropriate). And with this setup, the only thing locked down owner-hostile computing devices would be necessary for is for the devices parents would want to give to their kids.
The only way to view a mandate for an architecture with the complete opposite information flow is as a push to start exerting top down control over what can be published on the Internet for viewing by everybody. Basically, a governmental repudiation of the idea of the Internet as a permissionless communications medium, in favor of decreeing it must be a sanitized kid-friendly space by default, only becoming less restricted after you share your real-world identity.
Could be a ploy to give the big commercial players more power while making life shit for FOSS and smaller players. I doubt so many grassroots movements gained traction around the same time globally.