To drive top line growth instead of increase unit production, PP wants to increase average selling price per unit and hence the metal choice. Recent price rise for 5711/1A is further evidence of this strategy. Unsure if WG margin (%) is also better, they might be targeting improvement in margin also. Rolex clearly wanted to do the same using GMT as an e.g. (WG Pepsi, steel only in Batman), only to back track on that today.