I believe Rachio will inform the user of an overcurrent or short. However, a very related feature that would be nice, if it does not exist, would be to alert the user of an open circuit. In other words, a wire got cut or came loose.
Alternative to that is the flow meter would tell you theres no flow (solenoid never opened).
You are absolutely right. An overcurrent or short may also show up with no flow. Just another way of diagnosing an issue without extra hardware. Of course, I realize it may sound easier than what it really is.