It may or may not have gotten them rescued.... but being able to communicate with each other beyond line of sight, even if range is limited by terrain, is always a good thing IMO.

Even if rescuers do not routinely monitor all the possible channels of FRS, GMRS, HAM... if one or the other got rescued, even if the other party is out of range, they can tell SAR personnel that the other DOES have a radio, and what channel they're on. That immediately allows them to cover much larger swaths of land during their search pattern, as they may wander within radio range long before the could see you (if they could see you at all)

Even the cheapo radios may prove useful, and they're dirt cheap, so why not? (GMRS licencing is of course important to stay legal, although in an emergency I don't think I'd feel too bad about it).