I believe it started with the iPhone X once Apple introduced the Home Bar and gesture navigation instead of using a physical home button, so it's been a good few years since this started. With AIR 31, Adobe switched the behavior to apps automatically deferring edge gestures for full-screen apps, so you'd have to swipe up once to make the Home Bar appear, and then swipe up again to actually use the home gesture to close the app.
We'll still use that behavior on old legacy apps that weren't designed with the Home Bar in mind, since Apple doesn't want the Home Bar to be overlapping any UI, and some old apps just weren't designed to take that safe area into account. For our newer apps though we use that ANE and set it to ScreenEdges.NONE to get that normal one-swipe gesture back for full-screen apps, which also keeps the Home Bar on screen overlaid on your app at all times.