The logging APIs use special compiler features to evaluate the privacy level at compile time. As the diagnostic says, you must use a static (i.e., known at compile time) method or property of ‘OSLogPrivacy’; it can’t be a variable that’s evaluated at run time. The implication is that you can’t create your own wrapper for these APIs without using compiler-internal features.
It’s reasonable to file a bug to clarify the meaning of ‘static’ in this diagnostic message.