Developers who installed iOS 12.4 beta 1 after todays’s release are reporting that the EMV Express Transit feature that just went live in iOS 12.3, is missing from iOS 12.4 b1. These kinds of things can happen in early beta test cycles, my guess is this is why iOS 12.4 public beta has not been released.
What this really means is that the heavy construction and under the hood changes in Wallet and Apple Pay that started in iOS 12.2 and iOS 12.3, are still ongoing. It’s one more indication of many new Apple Pay things we’ll hear all about at WWDC19.
It is going to be a fun but hairy ride until Apple Card arrives. Be safe and stay away from iOS 12.4 beta and leave it for professional developers. Stick with iOS 12.3 and enjoy the great Apple Pay Express Transit performance.