I do, and I'm glad that you can acknowledge that.
Because that question is predicated on your redefining the term "official title" to mean "reference encyclopedia," when there's no justification for doing so and isn't what the text is saying. I'm not sure why you're so insistent on reading it in the most generous light possible, to the point of insisting that it has premises that aren't there, but the salient point is that they aren't there. It's not the first official title to talk about half a dozen campaign settings and what makes them unique, full stop.