The guy selling the accounts sells hundreds of thousands of them, and obviously doesn't get involved in the fraud itself.

This is why this whole thing is so strange, there's a bunch of people claiming that someone hacked teamviewer and is now using that access for petty paypal fraud instead of targetting the tens (if not hundreds) of thousands of PoS systems teamviewer is used to manage.

>Are they hoping that a small % of their victims won't notice the fraudulent transactions?

No, they certainly don't care if the payments get charged back or not. If they try to send money to their own account, it'll be suspended before they can actually withdraw it out of PayPal.

Instead in this case they seem to be trying to buy itunes gift cards, undoubtedly with the intent to sell them (on sites such as g2a.com) before they get cancelled.