Specifically, XDA found a pre-release build of Android Q that only features the home button, or “the pill” as they dub it. While the “recent apps” (which was removed in Android 9 Pie) and “back” buttons are gone, you’ll still be able to access their functions via gestures. So what do you do when you want to go back to a previous page? It’s surprisingly simple – just swipe the home button to the left.
All that said, it’s important to note that this is based on a leaked experimental build of Android Q. Google could decide that it doesn’t like the current implementation of gestures, and there’s a chance that the consumer version will be quite different. But we probably shouldn’t be too worried about it just yet. After all, phones that have access to Android 9 Pie are still few and far in between. (Source: XDA)