In the case of an edge-to-edge screen, the Home screen would also need some change. The reachability of the top icons is hard even on an iPhone 7. It’s not a good idea to push them up even more. However, aligning them to the bottom would be a pretty good move.
The augmented reality features would not only be accessible through Siri, but in all apps - if they have AR widget. For example, Facebook got a Friends Near Me
and a Live AR widget