Let's hope they do!
On totally another angle -- a couple (or ten !!!) threads ago, a poster familiar with hiking those area said that the areas where the couple had been hiking, etc., were not deserted or off the beaten path, i.e., they were popular and well-used. Apparently lots of hikers are in and out of many of those areas. So... IMO if Gabby were still alive and able, she could have asked or screamed or moaned such that some other folks would hear her. Certainly as soon as the hikers were able, seems to me they would have notified one of the LE sources, Park Ranger, medical rescue, whatever. If Gabby was okay, she probably would have asked to use someone's cell phone or asked someone to send a message home when the hikers were in cell range.
We don't know whether this has happened or not, but seems to me we would hear of it. If any of what I have just posted is possible, then it looks very dire for Gabby still being alive.
Just my thoughts. <sigh>