devtrackers.gg
These packs typically take a bit longer to show up on iOS devices. We are in contact with Apple to see if we can expedite this process. For tracking purposes we created a trello card here and will update when we know its available. https://trello.com/c/9LX3908f/945-the-batman-caped-crusader-pack-not-appearing-on-ios
Well good news! As I was writing my previous comment it seems it has begun to show up on iOS devices! You may need to restart the application but we have reports from our team it is showing up in store now!