Mobile phones continue to work during a disaster as long as the base station batteries hold out and that’s with cheap base stations serving very large amounts of idiot users using the cheapest of the cheap handsets limited by regulations. Why wouldn’t you be able to make this work indefinitely with a limited amount of trained users using selected, powerful expensive handsets.
In other words, a bunch of poor excuses made by coincidentally those same people who love to profess that privacy doesn’t matter as long as it’s someone else’s privacy.