The last two times I've connected my Edge 1000 to my Sony Z5 phone via Bluetooth and started the Garmin Connect app, it syncs the latest ride from the 1000 and puts up a message in the notification bar saying that an update is available for the 1000. However, the 1000 is already running the latest 8.10 firmware, and if I connect it to the PC and run Garmin Express, it tells me that the 1000 is up to date.
Same here with Edge 25. Mobile Connect for Android raises notification cca once per week that there's new software available for my Edge 25 and that I should update it. However I am running the latest software and when I try to update it, Express confirms the device is on the latest version. Web Connect also confirms the device is on the latest version.