1 big big side effect of disabling WMM: speed. My 5GHz switched back to 54 Mbps. See https://community.tp-link.com/en/business/forum/topic/151677 Switched WMM on again.

Same issue on my Omada-setup (OC200, EAP245, etc). WMM is configured for each EAP for each band. Go to your EAP, config advanced. After rebooting EAP's and iPhone, the privacy warning is gone.