I had the same thing happen to me with my Thinkpad Nano, and researching how to fix this made me realize pc manufacturer really don't care.
PC bricked from BIOS update are still ultra common.
I uploaded a dump of the flash [1] in the bad state and they somehow analyzed it and made a fix. Great for others I guess, but I'm still mindblown that the regular path would have been that this perfectly working laptop to this day become ewaste.
Being an embedded dev, I don't understand why there isn't a special USB-C protocol to recover bios over SDU/CC pins. Or some DFU mode you can boot into.