If the operators of the Skyliner will give accurate information to guests about the delay, then half the problem will be solved. But if they continue to give vague replies to specific questions (such as, Q: "How long will the gondola be stuck.", A: "Please stay seated as the gondola may start at any moment.") then people are going to use their cell phones to get real answers.
Disney has to recognize that people trapped in a gondola for a period of time need specific answers. If Disney doesn't provide answers, or they are very vague, or if Disney is obfuscating then guests will light up social media and 911 to get the answers they deserve.
It's incumbent upon Disney to keep the Skyliner moving and if it stops, then they must provide specific and accurate information to all guests in the gondolas as to the nature and time of the delay. For short and routine delays a prerecorded message is fine. For longer delays a live cast member should be making the announcements and be ready and willing to answer any and all guest questions and to ally fears and to talk the guests right down to the ground if necessary.
Also, only the guests stuck in the gondola can determine if there is a real medical emergency. And the bottom line is that it is better to declare an emergency and call 911 and then find out you didn't really need them than fail to call 911 and find out later that someone suffered a serious health problem due to delayed medical care. It is always best to err on the side of caution.