I agree.
All we can do is speculate, as Asobo will not likely be too open about rolling fidelity back. Bad business to admit steps backwards.
But I remember something like this happening before. Last year, when the GOTY and Xbox Edition rolled out, clouds were rolled back in detail on PC. Asobo never exactly said why this happened but it seems clearer in hindsight. They needed the game to work on the Xbox and the GOTY edition with all the new planes and whatnot, and clouds were a resource hog. They needed to be rebuilt to work on PC and Xbox alike.
Folks on PC were mad and blamed XBOX but now, look at the post above mine. Clouds are a selling point. They are better than ever.
This year, we have the 40th Anniversary and Asobo knew a bunch would return to try the new content, so they needed a working, stable sim.
And I suspect they rolled back Series X fidelity to guarantee smoother gameplay for returning players, while they worked out the kinks on fixing the notorious Series X Main Thread stutters, which are most likely LOD related. They definitely are on PC.
New and returning players are the least likely to notice the rollback.
I have to imagine they did this because they knew a fix was imminent but wouldnāt be ready in time for this important SU.
Speculation. But with precedent.