Developers must build apps using the iOS 13 SDK . If not, won't be accepted

Apple said developers had to develop any app submitted by the IOS 13 or iPadOS 13 SDK or later for an application for App Store review by April 30 2020. It won’t be accepted if it wasn’t.

Since iOS 13 is at 77% adoption and iPadOS is at 79% so all apps submitted to the App Store must use an Xcode storyboard that should be compatible with all size models.

For more info regarding the new app submission, please go through this link Apple’s developer site.