AS9100C, section 7.4.2 Purchasing information has a requirement for the organization to ensure that the PO is adequate prior to being sent to the supplier. Section 7.4.3 has the requirement to ensure that the purchased product meets specified requirements.
AS9100D, section 8.4.3 has the same requirements as 7.4.2. And section 8.4.2 has the same requirements as 7.4.3
There is not a specific requirement to track receiving PO confirmations from suppliers in AS9100C or D. Be sure to review your internal requirements as it may be stated there.