I am not using beta Xcode software. I have always been able to submit to the app store regardless of mac osx version, as long as I used the latest GM Xcode release. All of a sudden, from what I can tell, a few days ago itunes connect is now failing when submitting for review.
Before you respond by "You cannot use beta software to submit applications to the app store" please read the official copy from Apple.
Submitting Apps Apps that are created using beta versions of Xcode or that are built for beta versions of operating systems will not be accepted on the App Store and Mac App Store. Apps that you submit should be developed using the latest version of Xcode from the Mac App Store and should be built for publicly available versions of iOS, OS X, and watchOS — except when GM seeds are available. When a GM Seed of Xcode becomes available, use it to develop your app for submission. When GM seeds of iOS, OS X, or watchOS become available, build your app for these versions.
Nowhere in this text requires you to build ON publically released versions of OS X, and has never been the case.
Radars filed #22116787 and #22116676
