Read the RFC! That’s just the audit trail, mentioned therein.
I was actually involved in purchasing those machines, and the software that runs them. I can promise you that there was nothing nefarious going on. We could barely get the basic functionality out of those guys; they certainly weren’t achieving any SHIELD-level information gathering. There was nothing at all in the Statement of Work to suggest a communication between the credit/debit card system and the printer.
Those credit/debit systems are highly regulated and the communications connections are completely separate from everything else going on inside the box. They do nothing else except to process your payment.