macOS Sonoma does not allow TestFlight betas

When submitting a Mac app to TestFlight using the latest betas of Xcode and macOS (macOS 14 beta 6, Xcode 15 beta 7) I get the following error message:

Asset validation failed

This bundle is invalid. Apple is not currently accepting applications built with this version of the OS. (ID: fd741cba-f0da-4055-8bda-e8f7da257080)

However today there also was a TestFlight update with the following message:

You can now submit apps built with Xcode 15 beta 7 using the SDK for iOS 17 beta 7, iPadOS 17 beta 7, macOS 14 beta 6, tvOS 17 beta 7, visionOS beta 2, and watchOS 10 beta 7 for internal and external testing, […].

While it does not explicitly state that I can submit apps while on the latest beta, I highly doubt that many people are submitting macOS apps without running them on device. I suspect that most people are able to submit betas while running Sonoma?

I would expect this to have to do with the app containing a Finder Integration target and this being some weird edge case that Apple does not catch.

In this post @eskimo says that you cannot submit anything from the macOS beta? Is that true even for TestFlight builds? User @ingconti says in a reply to that post that they got it working.

(Side note: I already submitted this issue when it first happened, but I accidentally accepted a reply as an answer although it is not and I cannot undo it)

macOS Sonoma does not allow TestFlight betas
 
 
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