Xcode 16 RC uploads unsupported

We’re seeing app uploads built with Xcode 16 Release Candidate being blocked now Xcode 16 final is out. Is there something terribly wrong with the RC we should know about? The error message says submissions are unsupported using beta versions, neither of which is the case.

The full error message is:

Asset validation failed (90534) Unsupported SDK or Xcode version. Your app was built with an SDK or version of Xcode that isn’t supported. Although you can use beta versions of SDKs and Xcode to build and upload apps to App Store Connect, you need to use the latest Release Candidates (RC) for SDKs and Xcode to submit the app. For details on currently supported SDKs and versions of Xcode, visit: https://developer.apple.com/news/releases.