I sense a theme here . . . Apple is to blame and WD is simply an innocent third party trying to make a living. In fact, MS and Apple have for decades updated their OS with the expectation that third parties ensure they continue to provide paying customers updates to software. That is the whole point of MS and Apple releasing beta versions to developers for months so that this important compatibility can be accomplished. Further, it is by now widely accepted and expected that third party developers and software companies update their software rather than MS and Apple ensuring that all the thousands and thousands of products are compatible with the newest versions of the OS.
Bottom line, High Sierra was announced months ago and a company with WD's resources should have foreseen this issue with one of its heavily promoted products. As for asking WD, I have and you can see their responses in my initial message.
As for who is to blame, I would tend to think that apart from the way the industry has developed with MS and Apple driving the development of OS, the blame has to be placed on the company which I have paid when purchasing their product just a few months ago. In fact, as this product has a one-year warranty, WD must ensure it is providing the proper updates so that its products work with the two leading OS.
Finally, as for checking compatibility, the link sent above has not been updated since June 2016!
I assume I am not the only Mac user with this compatibility issue. We shall see . . . .