The com.apple.MobileAsset.MobileAccessoryUpdate.A2564.EA
MobileAsset type contains firmware updates for AirPods (3rd generation).
It's published in mesu for iOS (manifest) and macOS (manifest).
The manifest was first published by 25 October 2021 , around when the first firmware update was released.
For the release history of AirPods (3rd generation) firmware updates, see the OTA Updates/AirPods (3rd generation) page.