My understanding is the drones are meant to give firefighters eyes on an incident before they arrive on-scene. Emergency calls can be notoriously inaccurate, from giving wrong locations to not describing things clearly.

If firefighters can see what they’re responding to even 5 minutes before they get there they can start preparing in advance. Maybe they need to call in additional or different resources. Maybe the actual incident is down a different dead-end street. If the drone has an infrared camera then it also might tell them where fire hotspots are, or the location of victims, etc.