FWIW, I did install Rory Mcilroy PGA Tour on my Series X a couple of days ago to see how it would be affected on the latest and greatest hardware. I already owned it from the week it was originally released, back in 2015, but had retired it less than a month later. I never could by into its swing interface for various reasons.
Anyway, it did get the benefit of the Auto-HDR, but in this case I'm not so sure that the Auto-HDR actually turns out to be a detriment to the looks of the game, at least while in motion. I always thought there was an annoying bit of shimmering in the graphics of this game that was attributable to its texturing. It looks fantastic in screen shots, but leads to some flashing between light levels that looks unnatural. The range of the flashing is seemingly broadened by the expanded HDR, making it even more annoying, IMO.
The game loaded a ton faster, which is good because it was subject to some very long load times. I couldn't tell any difference in the animation of the game, nor the feel of the swing on the Series X, but I didn't expect any because like PGA TOUR 2K21, this one is just 'backward compatible' with no additional Series X enhancements.
I won't be going back and playing RMPGAT after trying it again over the last two days. It's just not my cup of tea. The swing interface doesn't work for me and I don't like the camera presentation options, nor the angles and cuts the one's provided afford. Finally, the putting in this game has less feel than I recalled from 5 years ago.
I'll say this for the game though, I liked the animation level, realism, and movement of the galleries and the quality of the graphics in still shots. If I was a 3-click player, I'd probably still be playing the game though. It might have the best 3-click interface I've ever seen in a console golf game, but unfortunately 3-click quit floating my boat in the year 2000.