This could be a very good thing. The devil is always in the details, of course. But it looks like it doesn't rely on SMS (texting) or data services (mine is usually turned off). All it needs is an LTE capable phone and a connection to a tower.
My understanding is that with a phone that is turned off, the alert will be generated on the phone when you turn it back on. And if the sound is turned off, you would at least get the message to read.