I have a 5G phone (Samsung Galaxy Android) on the T-Mobile network and it has always been my experience that I have no service at all when visiting the museum. In fact, I typically leave the phone in the car, because it is useless dead weight when hiking around. Anything that can be done to improve coverage is a good thing, particularly with all of the events that the museum is holding and with the hiking trails. If visitors or hikers have some kind of problem, they can summon help quickly. In the event of a medical problem, it can make all the difference in the world.
Cell phones can also be used to locate people, even when they are not able to make calls themselves. I am the Director of Emergency Services for New Hampshire Wing, Civil Air Patrol, and we used CAP's Cell Phone Forensics Team to save a guy who had become trapped on Franconia Ridge a couple of years back. We searched by air (visually) for an entire day looking for that guy and could not find him. Shortly before sunset, the Cell Phone Forensics Team came through with some coordinates, which we passed on to the NH Army National Guard. They sent a UH-60 Blackhawk up on that ridge at sunset, with the crew wearing Night Vision Goggles. When they went to those coordinates, the helo crew spotted a guy shining a flashlight at them, and were able to put medics down on the ridge to get the guy out. Even weak cell phone coverage is better than none at all.