What happens here is something called “account updater” that banks and networks use to notify payment providers that the customer has changed their card, and send information about the new card, so Google Pay would then link their token with the new card and the existing subscriptions continue uninterrupted. Likely there should be a way for the customer to opt out of this, but I don’t think there is. I implemented this integration with JPMC once and this all happens automatically via direct integrations between issuer and payment provider.