You are right, I over-interpreted from what I read elsewhere.
They only claim this:
Google Play System Updates, launched last year, lets us expedite updates of core OS components to devices in the Android ecosystem. In Android 11, we more than doubled the number of updatable modules, and those 12 new modules will help improve privacy, security, and consistency for users and developers.
And though that obviously is an improvement it is not including everything. 😥