Having someone answer and provide updates or screen for new information is valuable. For instance someone calling can know exactly where the shooter is. Or it could be something related. Information is valuable. What's the alternative? Not have someone pick up the phones? No matter how much you over staff there will be times where peak volume will be more than you can support

This assumes that LLMs can do those things. Given day to day experience with "chat bots", they can't. The LLM eii be circular do nothing of value then route your call to a number where nobody picks up.