If you collect your car from the 1st of September up 2021 up to the 28th of February 2022 you will get a 71 plate.... 1st of March to 31st of August and it will be a 22 plate.
Nothing to do with the VIN. The date of first registration will dictate the plate. ie, if you told them you would collect the car on the 28th of February 2022, they will assign you a 71 plate but if for some reason you miss your appointment dont collect the same car until the 1st of March it will then be on a 22 plate. The car is not registered until you are there/have it delivered and sign it off. They can assign you a 22 plate in February if your collection/delivery won't happen until March.
Hope this makes sense