Ok. My current theory is that this occurs when connected to a USB-C PD device that does not fully comply with the USB-C PD spec. Occasionally, these devices may be sending weird power signals to the Mac disrupting sleep/wake cycles in unexpected ways leading to the issue. I cannot reproduce the SOCD report error at this time.
There is a long thread about Dell U3818W and U3419W monitors not following the spec as advertised leading to the sleep/wake power signal issue arising on Macs. The response from Dell on the matter is laughable.
This is likely correct; and I'm quite sure it applies to
all USB ports, not just USB-C.
EDIT:
Just got this issue for the first time after 9 months owning an M1 MBA...
Connected to OWC Travel Dock with a USB-A mouse and USB-C PD plugged in... Connected another USB-C to Lightning to my iPhone 11, started syncing when suddenly a crackling sound occurred, display contains graphic artifacts, then my MBA promptly restarted...
On the first ever time this happened, I had a similar issue with audio crackling, seemingly from the onboard speaker despite a speaker being plugged in via the Headphone port, alongside a long reload time and a green screen. The other two times it was an instant restart, no warning beforehand of any real sort. Furthermore, I
used to get pink-colored visual glitches (2-3 pixel wide distortions that'd flicker on and off) for a short time after boot, but this mostly stopped when I switched to the correct refresh rate for my monitor (it's at 75 fps, but the computer didn't automatically pick that up) and after a system update.
I suspect said update may have made the issue more stable, as early in my Gen 1 Apple Silicon Mac Mini's usage (like March of this year?) a software/firmware update caused large amounts of visual distortions and took quite a bit longer than I would've expected, but graphical/sound stability and crashes became less common overall afterwards; furthermore I haven't seen anything like that when updating since.