Apple starts accepting App Store application for iOS/iPadOS 17, watchOS 10 and tvOS 17. Apps should be built with Xcode 15 Release Candidate.
Xcode 15 release is expected on September 18 together with OS releases.
Starting in April 2024, apps submitted to the App Store must be built with Xcode 15 and the iOS 17 SDK, tvOS 17 SDK, or watchOS 10 SDK (or later).
Apple Developer
Apple Developer: App Store submissions now open for the latest OS releases
Recommendations
Developer:
Verify apps with Xcode 15 Release Candidate, be ready for App Store submission.QA engineer:
Test apps on current releases and Release Candidates.PM/DM:
Consider submitting apps targeting OS update availability.