A: Then you are swapping the entire identity of the Mac. The serial moves with the M1 chip. You now have the same problem, just moved to a different shell.
This is the darker reason. A stolen MacBook is locked to the original owner’s Apple ID. The thief hopes that changing the serial number will fool Apple’s servers into thinking it is a new, unlocked device. On Intel Macs, this was a grey-market service. On M1 Macs, this is effectively a dead end. macbook m1 change serial number
If a serial number is modified without proper cloud clearing, the next macOS update or system restoration will trigger an immediate Activation Lock, freezing the device. Summary: What Should You Do? A: Then you are swapping the entire identity of the Mac
Unlike older Intel-based MacBooks, where third-party technicians could use specialized software tools (like Blank Board Serializer) to write a new serial number onto a blank motherboard, Apple Silicon laptops handle security differently. This is the darker reason