Job Is Making Us Show Up For On Call Shifts?

I work at a sports arena in Florida and as the new season has started, management has gone completely off the walls when it comes to scheduling. They took away our ability to get shifts covered by other employees, they are consistently adding / removing people from the schedule just hours before their clock in time with no communication at all so they show up just to be sent home. They absolutely cannot get it together. Last night around 1am they sent us an email telling us that we now have to physically show up for “on call” shifts. On call shifts were previously rotated through employees who would call in and they would tell us if we were needed for that day’s event or not. Is this even legal? There are many people who drive close to an hour or even more to work, and they are asking people to show up and stand around to wait and see if they are needed?