I wouldn't be surprised if they avoided routing a race course through Galaxy's Edge, at least initially. The predicted crowd levels for GE are already expected to be high enough that they won't want to make the problem worse by cordoning off part of GE for a race, even in the "slow" season. The only option might be to have GE near the beginning of the course, so the racers are cleared out by park opening, but that creates a new problem of course crowding. I still remember the first Star Wars Dark Side Half, which began in the Epcot parking lot and hit the walkway between Epcot and Studios in the first 2-3 miles. That was an epic disaster, having that section so early in the race before racers got more spread out. RD didn't repeat that mistake for the next Dark Side, thankfully. It'll be interesting to see if and when they incorporate GE into the race courses.