Because the shutter is fixed, the exposure time of each frame is directly related to the frame rate. Lower frame rate = longer exposure = more motion blur in the frame. Shorter frame rate = shorter exposure = less motion blur in each frame. You need more light to shoot at a higher frame rate to keep the same aperture setting.
So, if they do project this at 24 frames per second (by throwing away half the frames in post), the frames will not have the necessary motion blur and it will actually look worse because half the frames are missing. This could also probably be fixed in post, but that would be a pretty big hack for such a large production.