The VR/AR viewer should be included with the pro license for MAC!
It is currently only available with Windows, it should be available for MAC too.
There are two different things. The AR feature is an add-on to the mobile app, and in the product matrix it’s described as “AR mobile viewer”. You do get that as a subscriber to any variation of SketchUp.
The VR headset support, which includes mixed reality headsets such as Hololens, is Windows only, because the support for such headsets is Windows only.
What about for Oculus products? They are MAC (iOS) compatible. Oculus is quickly becoming industry standard, at least where i am. For now i have to use a third party extension and it’s an absolute pain.