In fact according to Apple’s developer page (via VentureBeat), the company has set a deadline for March 2019 for developers to ensure that all their apps are compatible and will support the new iPad Pros and also the iPhone Xs Max.
According to Apple’s message on its website, “Update to Xcode 10.1, which includes the iOS 12.1 SDK, and build your apps. Starting March 2019, all iOS apps submitted to the App Store will need to be built with the iOS 12.1 SDK or later, and support the all-screen design of iPhone XS Max or the 12.9-inch iPad Pro (3rd generation).”
Apple has made some pretty major changes to its products that were launched this year. The iPhone Xs Max has a new 6.5-inch display, and the new iPad Pros also come with changes of their own. There is the new 11-inch model, and while the 12.9-inch model’s display size and resolution remains unchanged, the removal of the home button means that space for gestures used to interact with the app need to be included.