This sounds like you were making some guesses, which turn out to be incorrect. You are saying that AirPods cannot connect to non-Apple devices, which is untrue. They function as regular Bluetooth headphones for any device.
You said when I asked which should get reported “Whatever is reported to iPhones. It's not an excuse to block non Apple devices from reading battery level”
Exactly how is Apple going to send information to none Apple devices using the BT protocol in a method that they can understand?