Shipping Universal Apps

When it comes to App Store distribution, Apple generally does not allow apps built on a new SDK (like Big Sur, macOS 11) to be submitted to the App Store until a few days before general release.
Since you can't build Apple Silicon apps on an older SDK, this seems to apply.
An email or other communication usually goes out to developers when the gates have been opened for submissions.

As for self-distribution, Xcode 12 for macOS Universal Apps Beta is not covered by the same super-restrictive NDA as the Transition Kit itself, so building and low-key distributing to developers with that is less of an issue (though you can't quite TEST what gets built...)
I'm not a lawyer, so take this all as non-binding feedback :)

The macOS 11.0 SDK is *beta*. There is no guarantee that apps built against a beta SDK and using new ABI will work on future versions of macOS. If your app uses only ABI that has shipped, you should be fine (but then why not just use the old SDK).

In short, a beta X SDK is only expected to work with the exact same OS version.

Thank you both.
I have read and re-read the DTK NDA and there's absolutely nothing about distributing Universal Apps in it.
None of my apps is distributed through the App Store. I well understand the limitations which that might impose.
I am fully aware of the limitations of beta versions of Xcode, thank you. As the current release version of Xcode can't build Universal Apps, there seems little point in trying to build them with it. The whole point of building apps with a beta version is to test them, and users (suitably warned) are the best way to do that, particularly on Apple Silicon.
Anyway, I've released five apps and will continue to get more built as Universals, tested, and notarized. So far so excellent.
Howard.