More discussion in the dedicated thread on this:
As to ATC, they have no role. The airshow management “owns” the airspace within a few miles of the airport and a few thousand feet up of the duration of the show. The usual FAA ATC is out of the picture.
There is a script and somebody (the “air boss”) in charge of managing the gaggle. But his role is essentially timekeeping and such. “OK, mass gaggle of bombers and fighters: the preceding aerobatic act is just ending. Leave your holding patterns now and proceed to show center getting into your positions along the way per the show plan.”
Everything after that in all its detail is down to each pilot doing the right thing at the right time versus all the other airplanes and the ground to end up in the right 3D place versus everybody else going the right direction at the right speed and all at the right time.
@Magiver’s right about the result of all that maneuvering. But he leaves out the part about how everybody gets from where they were to where they are supposed to be. Which should be deconflicted by altitude until it isn’t.