The main context here are the people who work for delta, especially the pilots, flight crew, and flight dispatchers. They are the most important people and have interest in passengers because they want passengers to keep flying with delta. At the same time they have little power in changing the airline
The subjects in the situation are definitely people like businessman who fly all the time. People who are frequent flyers want the quickest and easiest route from point A to point B, and this social media post gives Delta the right to say they can do this. Vacationers are also subjects because they fly for their vacation and want a great airline.
The crowd would be people who do not fly because they have little interest in airlines and even less interest in who is the best airline. People who are scared to fly fall into this category to because they will not even pay attention to airline news.
Players are the higher-ups in the airport because they have the most power in changing the airline and a lot of interest in what others think of their airline. Delta being the best airline will bring paying customers, and that is important to the higher-ups.