If you register your system using Windows Autopilot Deployment, and the system needs the motherboard replaced or the system needs to be exchanged for a replacement system, then the system must be de-registered from Autopilot before the service or exchange going ahead.
Failure to de-register will cause you further problems on the repaired/new system, as currently, the registration follows the motherboard unless it's de-registered. Once the repair or replacement is complete, your Autopilot registration can be reset.
If your Microsoft Autopilot registered system is currently waiting for work be carried out to its motherboard or you are waiting on a replacement system, then you can get instructions from the following Microsoft document on how to ensure your system is de-registered from Autopilot first: