As per a latest blog post for developers, Google is making it clear that Android P phones will not have more than two cutouts. Similar to all the existing smartphones with notches, Android P will also require developers to use the space around the cutout for displaying status bar information only in normal mode - the status bar should be as broad as the notch.
In a blog post on its Android Developers website, Google detailed how developers should modify their app's code in order to incorporate up to two notches, and displays with 18:9 or more aspect ratios. That means no more than two cutouts on a device, and multiple cutouts can't exist on a single edge.
That said, Google has now stated that while it is fine to have one or even two display cutouts in Android devices, having more than that is definitely not permitted.
If any of you insane phone makers are thinking about building a phone with three or more notches, probably don't do that.
First, devices must ensure that their cutouts do not negatively affect apps.
The good news for those developing for Android P is that by default "the status bar will be resized to be at least as tall as the cutout and your content will display in the window below". Google says it worked with device manufacturer partners to establish a set of practices for notch implementation so that the hardware design won't conflict with software rules built for app devs.
Android P engineers recently addressed cutout design questions in an AMA on Reddit, noting common problems with notification icons merging with system icons, in turn confusing users about the importance of the icons. While we have seen the number of notched Android phones growing increasingly this year, consumers are still divided on the notch. Smartphone makers could go that way in the future, leading to smartphones that are filled with entirely unnecessary notches. There can only be a single notch on each edge of the display.
Why have a notch when you can cut holes in a full-screen smartphone display?