They moved on to using alternative orb services and suppliers to bail out of debt. There are various methods to get fraudulent orbs, and various marketplaces you can access these different means.
Most fake whales that want to continue playing have turned to a different fraudulent orb supplier using a safer method. Fraud is never going away. It's up to Blizzard to stay on top of it.
But it does seem that the pre-authorization fraud (where your bank communicates to Blizzard it will process the transaction, but stops and asks you if it should do that, has been fixed). So a major source of fake whaling has been stopped.
This doesn't stop black market orbs however. But pre-auth bank fraud was a major source of orbs, and Blizzard does seem to be signalling that's come to an end.
Previously you could buy 5k-7k reso, as long as you can float the credit, and then just chargeback/block the transaction. This had no negative impact on your game. Negative orb count had no penalties. Now you don't necessarily gain anything from doing this type of fraud because you are set negative faster.
Players who seek to pay 2-5 dollars for 10,000 orbs will still be able to access those prices and buy themselves out of debt if they chose, at their own risk.
It's been confirmed on reddit that frauds are moving toward using new vendors to buy themselves out of debt.