I noticed hiking yesterday a sign for UHF deep in the forest, presumably for emergency fire response at this time of year (summer).
Ironically the mobile reception is sub-par in East Gippsland but I got a, relatively, strong 3G signal from the top of Genoa Peak, where the nearest phone tower is perhaps 10km away on the valley floor.
This already exists in many parks. Which is why it's slightly puzzling that first responders would be stumping for this.
My guess is that hikers don't carry a UHF/VHF radio, don't know how to use it, or don't know the right channel to call for help. Most people have a GSM/CDMA phone to call for help.
So, not so much help for the first responder's communication, but helping to alert the first responders.