I would advise doing nothing @ all, at least for the moment, while waiting to see if Amazon dispatches a Notification that the Brazilian Marketplace account requires Credit Method Manager to be updated.
This presupposes that you do not already have one of the multiple forms of Offer-Listing synchronization in place for the Canadian and/or Mexican Marketplaces.
It is often recommended to follow the same methodology that has worked in the past for those latter two, breaking all synchronization possibilities and placing the Brazilian account in Vacation Mode, but @ this point in time I really think it’s better to wait & see what develops, as things are obviously in a state of flux.
On a related note: there have been multiple reports that when Amazon Sao Paulo attempts to ‘ping’ a credit card for verification purposes, a Fraud Alert is issued to the holder, so it might advisable to proactively notify your institution of that possibility occurring at some unspecifiable future date.