They might be able to see players getting scragged thenThe bounce worked when all AFL grounds had cricket wickets in the middle of them and the umpires could get it high in the air and let rucks come from long run ups to compete for the ball.
Most AFL grounds have drop in pitches now which makes the grass far softer and there is the centre circle to prevent rucks have a long run up.
At the start of each quarter, each half or even just the start of the game would be a nice tradition but otherwise there's no need for it. I do hope the umps can throw it up high enough so the rucks are encouraged to jump but most of them do and by training for throwing it up not bouncing they can get more consistent.
Personally I love a good preseason gimmick so I'd actually be getting a drone to drop the ball in the centre square and that way umpires can stand away from the stoppage and watch the play as the ball gets dropped for them.