As spotted by 9to5Mac, there appears to be an option in the beta of iOS 12 that reveals that the platform could support automatic system updates. As it stands when it comes to updates on iOS devices, Apple either prompts users to install the latest update, or they give users the option to schedule it for an overnight install.
However this requires input from the user via the notification prompts, but this feature seems to suggest that it could bypass it entirely. macOS currently supports automatic system updates and will require computers to be connected to a power source. Assuming that this feature is indeed what we think it is, chances are it might have the same requirements.
However given that Apple typically prompts users to accept various terms and conditions before installing an update, we’re not sure how that will play into this automatic update feature, but we guess we’ll have to wait and see.