Hi,
This announcement appears on the appstore:
We remind you that, starting from March 27th 2019, all new apps and updates for iPhone or iPad apps, including universal apps, will have to be developed with the iOS 12.1 SDK and support iPhone XS Max or iPad Pro (3rd generation) of 12.9 inches. Screenshots for these devices will also be required. All new apps and app updates for Apple Watch will need to be developed with the watchOS 5.1 SDK and support Apple Watch Series 4.
Do our app continue to be compatible or do they need to be modified?
Thanks