There's no notification, it is best to keep an eye on our wiki downloads page or checking RMS daily to see if there's an update. As I said, FOTA does not automatically check is there a new firmware available, it checks it manually once you enter firmware update WebUI page or check RMS. So it really doesn't matter if you turn FOTA on or off, it will only cause you to see or not to see the updates and packages available.
EB.