I understand what you mean, and I can kind of agree. On top of that, it's not anything we haven't seen before. It just looks like what we saw in the trailer but edited a little bit.
I do concept art too and while it's nice getting something at all related to the game I missed the old Bungie days and the old 343 days during the time of the Anniversary games and Halo 4 where they showed us weapon, armor, vehicle and location sketches and renders and whatnot on a consistent basis and we got to delve a little bit into the creation and work behind the games. This is less of a concept for anything because we already know what a Halo looks like. Funnily enough right before news of the concept art dropping I was browsing old concept art by Shi Kai Wang and drawing my own Halo related concepts. Those drawings still blow me away today and I felt immense disappointment when I saw the Infinite "concept art".
Also if this is indeed a "concept" for what to expect (in terms of what the skyboxes may look like.) than I'm a bit disappointed. It looks amateurish, the perspective is weird and the way its laid out is wonky. It's the same way in the teaser too. If you notice, the "mountains" in the foreground (actually not even. They sit on the horizon line, which makes it look worse.) DWARF the continents of the ring in the background. The mountains on the horizon line should be smaller and sitting in the background itself. (Physically on the ring in the background.) The mountain looks like (for a lack of a better term) it is overflowing off the sides of the ring. The ring should not be rising up from the horizon line in the way it does and should probably have a wider base. The way the Halo ring is set up in the distance looks alot less than being on some celestial body it literally looks like a big building off in the distance. It breaks the illusion of scale and grander. This also applies to the trailer (this concept art looks like it was taken out of the trailer anyways.) because it happens there too where trees and the mountains dwarf the continents. Hopefully it's a stylistic choice and they fix it in the actual game. Also the ring itself is alittle bit too flat, you don't notice a curvature and since the base is slim it makes it feel if it doesnt curve above you in a circumference like a ring would if you say inside of it, which probably doesnt make alot of sense but its hard to explain.
I dont know, as an artist maybe I'm just being nitpicky but that's what I see and I cant unsee it. If you study the picture than you start to notice that none of it really makes any sense.
Edit: I'm just noticing theres a Forerunner building sitting near the peak of the mountain on the right. Imagine you're to scale of the mountain and you're sitting at the peak looking at it... How BIG is that BUILDING?