The Anniversary Update (and previous Windows 10 edition updates as well) is basically a re-installation of the whole operating system with the settings from the

The Anniversary Update (and previous Windows 10 edition updates as well) is basically a re-installation of the whole operating system with the settings from the old installation migrated to the new one. This migration is not quite seamless, always a few options/settings that have to be re-done manually for me. But that has nothing to do with this new cumulative security update model, it's not a full re-installation.