I'm in the same boat.
For what it's worth their website has a different date than the email we all received:
The grandfathering program will terminate 30 NOV 2022. After this date, you can no longer transfer your lifetime license from mccPILOTLOG to CrewLounge PILOTLOG! The mccPILOTLOG software continues to run and your lifetime license for mccPILOTLOG remains valid, but the grandfathering program is terminated!