I don't think North America got it because physical version sales are on life support, digital sales reign king here in the States. Retailers here probably didn't think it made much sense to order the PC versions. It is possible that the physical sales for Witcher 3 base game didn't do to well here in the States. Just a theory of mine.
I am glad I ordered the cards through that deal they had prior to launch of the expansion. I just got my cards yesterday.