Hi! I have the following notification "Android 5.0.1 System update downloaded and verified.." on Nexus 9, but I want to avoid the upgrade, by the moment I disconnected the wifi connection and set the "auto-update" from Play store to "do not auto-update apps", but I don't know if the android version will be updated anyway.
All other qualifying Nexus devices have received the 5.1 update so far (the N7 2013 variants most recently). So it looks like Google will now focus on the N9 Finally!!!!!
I'm pretty sure the issue is with HTC, they had driver issues and so Google decided to not hold up the other devices while waiting. The N9 5.1 update has been in test for a while now, so hopefully it won't be long, but ultimately the driver builds are on the OEM. Since HTC is also building their N9 alternative similar to Asus I would suspect that also added to some backlog.