Google has revealed it will make it a requirement going forward for device makers wishing to use Android 7.0 Nougat (and presumably above) for their handsets to support the software's new notification features.

Google released a new version of its developer guidance documentation, the Compatibility Definition Document (CDD) for Android. The CDD describes what developers and OEMs must do to achieve Google's official Android certification and support (with the support including things like access to Google's official applications and services suite, and the Google Play app and content store/ecosystem), as well as things that are optional. In short, without the certification, OEMs would be putting out a pretty featureless Android phone on the software level.

The latest update to the Android 7.1 CDD includes this:

"Handheld device implementations MUST support the behaviors of updating, removing, replying to, and bundling notifications as described in this section.

Also, handheld device implementations MUST provide:
•The ability to control notifications directly in the notification shade.
•The visual affordance to trigger the control panel in the notification shade.
•The ability to BLOCK, MUTE and RESET notification preference from a package, both in the inline control panel as well as in the settings app."

That means regardless of what kind of features or launchers or UI skins an OEM wants to put on a new phone, they will need to support these very useful interactive notifications. A good move from Google.