iOS 13 brings multiple camera input, meaning apps can capture photos and videos from multiple microphones and cameras on one device (via 9to5Mac).
Multiple Camera Input
Apple demoed this new feature at WWDC 2019, showing a picture-in-picture video recording app that recorded with both the rear and front cameras. The presenter was able to switch between the cameras at will during playback in the Photos app.
Developers can also control the TrueDepth cameras and use the Rear Wide and Rear Telephoto lenses. However, this will be limited to newer devices, like the iPhone XS/XS Max, iPhone XR, and iPad Pro.