No answer. It's happened to me, too: I updated to Monterey 12.3 beta 3 and it bricked my laptop. My own attempts at revive/recover via Apple Configurator 2 failed. They also failed at my local service center and after conversation with Apple they replaced the logic board. I misread the release notes on Monterey 12.3 beta 4 and thought that the issue was fixed but... yep, bricked again and requires logic board replacement. Apple developer for 36 years and have NEVER had software require a logic board replacement. Be careful out there. Also, I sent messages about this via the developer's Feedback Assistant app but have heard nothing in return. Also, there has been no acknowledgement in the subsequent release notes. I hope against hope that this is not a harbinger of disaster and will wait several weeks after public release before trying to update that development machine again (and just keep daily working on my 2019 MacBook Pro). Y'all be careful out there, too! https://developer.apple.com/forums/thread/701419