Message "EZZ8774I PAGENT POLICIES NOT PURGED FOR tcpImage: type" is written if the NOPURGE option is in effect - either configured or defaulted - on the TcpImage statement. The message is written for QOS even if QOS policies are not defined for the tcpImage. QOS was the first policy type implemented by z/OS and as such has some small differences in the way it can be configured/processed. So if you have NOPURGE in effect for your stack then the EZZ8774I message you are getting for QOS is expected.
The following are helpful references:
https://www.ibm.com/docs/en/zos/3.1.0?topic=messages-ezz8774i and https://www.ibm.com/support/pages/policies-are-not-purged-policy-agent-and-tcpip-stack-after-policy-agent-shutdown
Joyce Anne Porter