Strange nailed it. I wouldn't really call that a straight or upright shoulder; it's just not the big, laid back shoulder that produces hunter or dressage movement.
The whole reason you look at the shoulder confo in a jumper is you want to make sure the lifting mechanism works, that the horse can rotate his shoulder will enough to bring the forearm up past horizontal and snap his knees. Your guy does that very well, therefore his shoulder is fine. He may not have the long, sweeping, no knee action stride, but he certainly gets his forearm and knee up.
As Strange said, the forearm to cannon ratio is ideal, and that helps produce his excellent form.
I like the way his neck times into the shoulder, it just that his neck is underdeveloped and under muscled. You can change that with work pretty easily.
And, yes, he's a little butt high/built downhill. The real limitation there is that he'll struggle with dressage past 1st level. But he's still a wonderful prospect for hunter over fences, the jumpers, or lower to mid levels of eventing.
With that jumping form and a good brain, I'd take him in a minute.
BTW, there used to be a requirement that in order to post a confo critique, you had to be able to pick a horse out of a police lineup if the other suspects were a zebra, a giraffe and a cow. But that was too restrictive so it was eliminated.
(Of course, there are still very rigid qualifications to post jumping critiques.)