It’s possible this happened a while ago, but Apple updated its Feature Availability page with the information.
Apple’s going big on augmented (AR) and virtual reality (VR) with iOS 11, and it appears those plans include the Apple Maps app. It was discovered this week that Maps locations which currently support “Flyover Tours” will now have a VR mode called just “Flyover” (minus the Tours). When accessed, the user sees the traditional Flyover view, but instead of the predefined tour video, the view responds to the user’s movement and the position of the iPhone. While currently providing a VR view, it appears that future plans call for AR too, as you’ll get a warning while using the app if there isn’t enough light for the camera. Check it out if you’re running the iOS 11 Beta.