As envisioned by Ed Greenwood, indeed. But by the time you get to the 3rd edition FR book, the point of each region has become buried under a heap of dry statistics.
The new book, by focusing of five distinctive regions, clearly wants to get back to the idea of “why set your adventure in this location?” And that means strengthening the themes that have become atrophied.
I used the Moonshaes in my first 5e campaign, but I stripped it back to the original version, as I wanted a Celtic setting closely tied to the the Feywild (I know it wasn't called that when the Moonshaes was first created). I threw out all the nonsense with vampires and stuff that it had acquired.