When connecting Citrix VDI with MacOS endpoints, Microsoft Teams running in the session is always shown as "Not optimized".

Microsoft SlimCore Optimization is currently available only for Windows endpoints. Thus, those MacOS endpoints have to use Citrix HDX Optimization approach.
However, "Microsoft Teams redirection" policy setting was explicitly disabled from Citrix Studio policy (by default, it is enabled). That results in Microsoft Teams didn't load in VDI mode and the optimization didn't take place.

Re-enable "Microsoft Teams redirection" policy setting in Citrix Studio policy. Then, Microsoft Teams Optimization starts working for MacOS endpoints.

The article describes a Microsoft Teams NOT optimized issue due to a misconfiguration in Citrix policy.

https://docs.citrix.com/en-us/citrix-virtual-apps-desktops/multimedia/opt-ms-teams-new/ms-slimcore-optimization#citrix-workspace-app