https://developer.visa.com/capabilities/vau
https://developers.mastercard.com/product/automatic-billing-...
https://network.americanexpress.com/globalnetwork/products-a...
Lots of companies update your data already from this data, not just Google. I guess it may just be a new feature where we email you about it when it's updated.
Edit: fun fact, the UK banking system has this for when you move to a new bank: https://www.bacs.co.uk/accountswitchingservice
(I'm a Googler working on payments, who has helped maintain the Account Updater feature, opinions are my own).
https://stripe.com/blog/smarter-saved-cards
https://stripe.com/blog/smarter-saved-cards