For those running macOS Sonoma in virtual machines for testing, I found a workaround to enable beta updates within the guest operating system: https://github.com/insidegui/VirtualBuddy/discussions/194#discussioncomment-6406771
Upgrade to Sonoma Beta 3 within VirtualBuddy? · insidegui/VirtualBuddy · Discussion #194

I can't seem to figure out how to upgrade a working Sonoma install in VirtualBuddy rather than downloading a full restore image and starting from scratch. Am I missing something simple?

GitHub
@_inside @siracusa Reason #12,954 on why VMs need to support Apple IDs.
@chockenberry @siracusa Yup. We've been able to log in using the Simulator for a long time, I don't see why VMs can't use a similar approach.
AppleID Login failing in virtualiz… | Apple Developer Forums

@_inside @chockenberry @siracusa I expect they’re paravirtualize the login soon enough