What changes have the banks made to Maestro cards?

Got an email from Blizzard, and backed up on the forums, that recurring payments are no longer accepted via Maestro. And this is because "This is something that is beyond our control and is controlled by the banks (it applies for all Maestro users). You will still be able to use Maestro for subscriptions but you'll need to process the details each time the subscription ends. " What's changed in the banking system?