Hello everyone,
I just registered for this thread. At first: please apologize my english, I'm not a native speaker. And additionally I would like to point out my strong aversion against the people who complained against those people, who restored their new MacBook, just as
@groundedUX mentioned previously.
I was very miserable about the condition of my recently purchased MacBook, as no method of getting Big Sur back on the Mac seemed to work. Though I don't own a second mac, so I was not able to test out the method with "Apple Configurator 2".
I don't know if Apple fixed the problem at that exact moment, but I found a solution that got my MacBook running again.
Since I was able to delete the volumes in the Startup Options -> Hard Disk Utility but not the complete SSD (constant error -69877), I became suspicious and logged into icloud.com with my Windows computer.
From there I selected "Find iPhone / Find My" -> "All devices" (above) -> "Macbook XYZ" -> "Delete Mac".
It then said that the MacBook will be automatically deleted the next time it is online.
I turned my Mac on and it was brought back to the startup options. I opened Safari, just to be sure that the mac connects to the internet. After that the MacBook actually deleted itself - after rebooting I had to select the system language again and in the hard disk utility only the volume "Untitled" was visible below the SSD instead of "Macintosh HD" and "Data".
After that, full of hope, I clicked on "Install MacOS Big Sur" - and indeed - the installation passed without any problems. I am very relieved.
Try it out, the Apple Chat couldn't help me at all (even wrongly recommended shortcuts for the MacBooks with Intel chips, which, as we now know, don't work with the M1-MacBook) and only could have given me an appointment for next week Wednesday.
Please let me know if that helped you.