The main reason players would want to signal to the umpire that he got it wrong is to influence the next decision. You want the umpire thinking about flopping when Hawkins is next in a marking contest so that they actually see it. Shane Warne used to train umpires to see what he wanted them to see. ‘Ooh had that stayed a little lower he was out’ etc. how many times does a player who ducked and won a controversial free kick not gotten one the next time? Umpires realise after they missed one and look for the duck next time.The decisions made. Pretty much no ump ever looks up at the big screen, they just get on with the game. And they definitely can’t change any decision based on a tv replay.
Players also need to get on with it. Just focus on winning the ball at the next play. Sometimes the umps decision goes against us, sometimes it goes our way. It’s just the way AFL is.
The only thing the players should focus on is what they can control.
Certain players or teams might get lucky with the umps. But I can’t see what gesturing to an umpire is going to do about it. Apart from give up a 50.