When was the work done? Do you know for a fact the board was replaced with the new 64gb chip, not just an old 8gb one?
Why have you not made a warranty claim on the work done? That should get you to the front of the line
If your car is in good shape, maybe just go MCU2.
If you think your car is depreciating now, just wait until you get a replacement!
Just a note there are apparently two different series or builds of MCU1 really old cars such as mine (a 2012) VIN number 162 Signature had an emmc failure but the 64 GB daughter board replacement could not be done because my MCU1 was original. My only option was to replace the original daughter board with another 8 GB unit or replace the entire MCU with the upgrade which I did not want because I didn't want to lose my radios AM / FM and XM.
There is a path forward to maintain your radios with the current upgrade but that didn't exist at the time so I opted to repair my existing MCU and upgrade to LTE since I was still running 3G at the time. We'll see how that works out.