I'm not sure if that was so much the predator 'homeworld' as much as it was just a Space Station, or Military Base maybe, but if you're correct, and it was THE homeworld of the Yautja, I guess it fits them, advanced city and all.
And also, there was plenty of foliage and such. It was just hard to see because it was a drop and dark green color and the whole world had a orangeish-over-color to it. Play the movie and pause it when you see Wolf's ship leaving the landing pad... Then look closely to the left of the landing pad and 'GADUSH' there is plants and trees and such lol