According to the AMTK app, a test booking between GJT and EMY on the 19th of September shows "Sold Out", so apparently the dates are just being blocked out as fully booked in Arrow. No service whatsoever for those communities affected, yet discreetly noticed in the system so there's not a flood of calls inquiring about the service or lack thereof on those dates.
Also, for detour fans, the Borie site is the stop the Pioneer made when it technically served Cheyenne. It's in the middle of nowhere, so those hoping to see some of Wyoming's capital city will likely be massively disappointed.