I think that you might be missing the boat a little here. While VR and to a lesser extent AR are not yet mature environments I think with the release of devices such as the Oculus Quest VR headsets are gaining more traction in the market. I also think that Unity will be a key platform for developing VR programs, particularly for the kind of indie developers who seem to be prime customers for GameDevTv courses. Although the big development houses are involved in producing VR material I think that VR is still a wide open frontier for indie developers and it is probably this community who will be the drivers for innovation in much the same way they were in the infancy of PC gaming in the '70s and '80s. Of course there are difficulties, interfaces for VR headsets are a moving target and today’s top flight devices may well be practically obsolete in a few years, so such a course would need quite a bit of monitoring and amendment fairly quickly. Consequently it would need a fairly significant on-going effort to keep such a course relevant, but I think that it may well be worth the risk.
As to current training I think that the best course is to look at what is on offer from the manufacturers of headsets. Most of the bigger ones have some kind of Unity interface and often create videos on setting up a developer interface, so pick your device and go for it.