Notification importance controls won't work for most apps in Android O, and Google is fine with that

Android O is going to have a lot of neat stuff, including notification channels for more granular control over what apps can ping you about. However, developers need to get their apps ready by targeting Android O. Until that happens, notification controls will be hobbled in Android O, and Google won't be fixing this apparent problem.

There's a thread in the dev preview issue tracker that explains the problem in detail.

Notification importance controls won't work for most apps in Android O, and Google is fine with that was written by the awesome team at Android Police.