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.
Exactly how is Apple going to send information to none Apple devices using the BT protocol in a method that they can understand?
Each member of a coordinated set gets its own Bluetooth battery level slot, so there's no problem here. The spec supports this use case natively.