Still, it appears from Pascal's post that you got an OEM version.
I've not heard of such a thing when ordering directly from Amazon since they typically ship WordPerfect products they get from Corel (or sell legitimate downloads) and would reap a huge number of complaints and ill will if they sold an illegitimate Corel product. They discount products so deeply they would not need to do such a thing. (Just my two cents as a long-time Amazon customer.)
Some third-party companies -- particularly those selling software only on the Internet -- sell a "boxed version" that is really an OEM that they (or someone else) probably duplicated and shipped in a box. (Here, by "box" I mean it should be a retail box from Corel (as shown on their site) and not a plain cardboard box or sleeve.) Yes, it's WordPerfect Office, but it's probably not what the buyer thought it was. And if the company who sold it gets an occasional return -- well, it's the price of doing such a business.
You might have seen a recent post here on OfficeCommunity from a user that got caught in just such a despicable practice. The ironic part is that they could have got a WPX6 Home & Student Edition (nearly the same thing as the Standard Edition) for less than what they paid for the illegitimate copy they ordered -- and which gave them a huge headache.