USB-A refers to the physical receptacle on the v2. What is behind it electrically is unknown, but I would say that power and data are a good bet.
I hadn’t looked at my new v3 cameras yet, I see they removed it, unfortunately. But given the way the v3 interacts with the socket, I would say the same functionality is still there on the remaining usb micro, so my suggestion stands.
I agree there are use cases for the current method, that’s why PIR would be complimentary. BTW, just in case, are zombies warm blooded or cold blooded?