But they're gonna do fly overs either way. It's a way to let the aces touch a real plane every month instead of sitting in the simulator.
Is it a waste of money? Yes. But exactly 0 dollars will be saved when they do away with fly overs. Since fly overs are essentially 'G' rated bombing runs, they will continue, either way.
Once they are banned, the military will simply fly over deserts or bases. So again, they are no more a waste of money than anything else the military does.