Google has slowly expanded control over notifications in the last few major updates, culminating with notification channels in Android 8.0. In Android P, Google is testing a system to suggest blocking notifications from certain apps. Which apps? Any app whose notifications you frequently dismiss.
This isn’t the sort of feature that pops up right away—you have to use it for a little bit before you’ve swiped notifications away enough to trigger it. We’ve not gotten several reports of the red button (seen above) appearing on select notifications. If you tap it, the notification asks if you’d like to hide notifications from that app since you seem to dismiss them so much. You can either “Keep showing” or “Stop showing.”
The proactive notification button comes alongside a new list in the notification settings that tracks recent apps that have pushed notifications. That menu also has an option to quickly mute apps. The button in the notifications is much more discoverable, though. It’s just a bit too discoverable right now with the bright red look. Still, this is just a developer preview. The button could change or go away completely by the final release.