I looked into this. It seems this is something that was added in M pertaining to Doze and App Stanby modes and is not related to the new O background execution limits (which apply generally). In any event, app exemptions must be approved by Google so we've already crossed the open platform line. They do list that voip-style/message apps will receive approval if they can't use FCM for some technical reason: https://developer.android.com/training/monitoring-device-sta...