Yes, indeed, looking at the picture on the cover, one can see MAC/PC!
So what do I know?
Your response is very much appreciated, that’s what I know. 
I do not understand though why it is not mentioned on the Yamaha page!
I have been asking the same question since I started delving in to acquire more information. The Vocaloid seems analogous to “some ancient Asian secret” that information is available for but you have to do an extreme lot of digging to get the facts together. Before I actually started spending more time to acquire information, most of the information I acquired suggested and even stated in most cases that Vocaloid was not supported on Mac.
The other disturbing thing is that historically Yamaha and Steinberg have always “seemed” to work together for most of their product releases. For example, I have absolutely no problems acquiring information and support for my XF8 and Cubase; and I can readily find information regarding their compatibility, support and etc.
So why Steinberg isn’t providing any information regarding the Vocaloid packaged by Yamaha or vica versa is a mystery to me.
It is also somewhat of a deterrent for anyone in the US including myself considering purchase of the product because what I found clearly stated support under Cubase 7 and 8; so what about the inevitable Cubase 9?
If it’s this difficult to get information now, will I potentially be up the creek if I decided to upgrade to Cubase 9? I’d likely have no way of knowing except to try it and see; which is not the most effective way to determine compatibility between products.
So my conclusion so far is apparently neither Steinberg nor Yamaha seem to want nor offer much support for the Vocaloid product to the US, if any; or maybe in general, consumers outside of Asia. The product is obviously only sold out Japan from what I can tell. Who made that decision is beyond me and it’s very curious as to why.
I will follow your suggestion to hit the KVR forum to see if I can get a better grip on the subject, but it doesn’t seem very promising at this point.
Thanks Teacue!