Not happening. CAD data is still too messy to put directly into the sim - there is way too much overlapping and non-matching of stuff like foliage, or when temporary stuff is getting in the way of key objects. Another reason is textures, yes you can photoscan the entire track but that will be counter the purpose even of the optimization of UE5, see they optimized polygon calculation so much to keep the amount of super-high-res maps to minumum, and that's what occupying the most of video memory. So you still have to map some shared textures around the track, and good luck doing that over CAD data. Still even time-consuming perspective, building "clean" models over CAD data is much more efficient. Yet.
TBH i would rather see how much FS2020 is capable for racing sims. It has much better sky & weather system and graphically that's what occupying 30% to 50% of screen space all the time in simracing. We don't need need the streamlining that much (although you can argue that it would allow avoiding modelling far away terrain and objects), but the majority of UE features we don't need anyway, stuff like interactive or breakable structures that change the lighting etc. We need very specific features instead, like rubber, dirt, marbles and skids buildup, very neutral and natural PP, optimization for big grids while having big physical fidelity etc. But the polycount & light calculation optimization in UE5 looks very very impressive.
