A new discovery in the iOS 12.1 beta indicates the software will support 4K external displays – possibly on the new iPad Pro models expected to debut later this fall. Current iOS devices can’t support external 4K displays, even when using a Lightning to HDMI adapter.
This may support the idea that upcoming iPad Pros will offer USB-C, developer Steve Troughton-Smith suggested on Twitter. A virtualized 4K option appears when running Apple’s iOS Simulator, used to test out iPhone and iPad apps.
Apple is expected to debut new iPad Pro models this fall, possibly delivering new 10.5- and 12.9-inch models with faster processors, edge-to-edge LCDs, and Face ID, possibly in Landscape Mode. Code strings discovered in the iOS 12.1 beta indicate a “iPad2018Fall” device, which could support landscape Face ID.