Nice list. From what I've seen in a few games, it seems like Series S is roughly equivalent to Xbox One X in terms of GPU power and could match it like for like in resolution in most cases, but the devs seem to be doing what MS recommended they do, aiming for higher framerate and/or higher graphics settings from the PC version instead of higher resolution. It makes for a really nice cross-gen cross-section imo. We have:
Xbox One- Low graphics settings, low resolution, and frame drops on many games. Looking ready for permanent retirement honestly. I feel bad for devs that will be stuck supporting it for another 2 or 3 years.
Xbox One X- Low graphics settings, high resolution, and usually stable framerate. Still has a few years left in it I'd say.
Xbox Series S- Higher graphics settings, lower resolution, and stable framerates in most cases. Looks to be properly next-gen ready to me.
Xbox Series X- Highest graphics settings, highest resolution, and stable framerates in most launch games, with only a few exceptions. A proper next-gen beast, though it seems to be held back by an SDK that wasn't quite ready for launch, which is resulting in some optimization issues for some devs. SDK problems should be remedied by early 2021 hopefully.