I think they can just release another commemorative special edition bottle to mark their withdrawal. An etched bottle with a bunch of “scratch marks” where the Premier Grand Cru Classe used to be.
An interesting conversation with a knowledgeable friend. He feels Pavie would be crazy not to withdraw as well. The exclusive club is the former Grand Cru Classe A, and if they withdraw it can never be taken away.
If they withdraw, they lose their A status starting with the 2022 vintage. Only 2012-2021 will be at an A status. The same for any estate leaving the classification means they are no longer classified starting with the 2022 vintage.