Sagichnicht I'm unsure if it's that, even if typing in Matrix one person who helped also suggested that. It wouldn't restart by itself instead requiring battery drain for it to turn off again staying at the GOS logo. If anything, I tried to charge it minimally for repeated power on attempts since it can boot fast when colder and wouldn't have to wait long if stuck again. It was stuck again, not looping rebooting, for 3+ minutes with power on attempts after waiting for a little charge pausing boot. The logo would always be moving with a one-time stutter.
Currently, I'm pretty sure it swapped boot slots as it gave me 13 day old system notifications before unlock and had downloaded this update again waiting for a reboot after unlocking. Going to refresh backups to what I can just in case and I turned off automatic reboots for now. This was after getting to fastboot, charging for maybe 6+ minutes, realizing I can't manually swap boot slots with a locked bootloader, then turning it on again to see 4% battery quickly booted into on the previous update.