What is the temperature of the massive pots of water at hotels for cooking 10 poached eggs at once?
In scale operations, a large 'rondo' is usually used, and as the comments above indicate it is at 'simmer' which is essentially 212 F / 100 C. A small amount of vinegar is added to the water, which helps the loose parts of the egg white coagulate and gives a nicer shape to the poached egg.

Since the kitchen you describe has glass walls, they are taking extra care for the showmanship part of the operation, having eggs in individual cups to drop in the poaching vessel.

A large vessel is used to reduce the temperature rebound of adding the cold (maybe close to room temp) eggs. As each is added, it does not significantly reduce the temperature of the rest of the water in the large pot.

The fact that the water was clear means the station cooks are under directions to continually add vinegar and skim the water. After each egg, some bits come off that have to be cleared out. If the kitchen did not have glass walls, the water would not be that clear during a busy brunch !