Auto ND filter possible?

Ok so I'm wondering about the x100's ND filter, obviously a big use for it would be to allow you to shoot in bright light at wide apertures. I'm assuming if you try to shoot at 1/4000 @ f/2 it'll just show an error because of the lens/shutter design limitation. Could the firmware not be set to auto engage the ND filter in these situations and hence reduce the shutter speed enough such that you'd have a correctly exposed f/2 shot?

Is there something ive missed, a reason why that wouldn't be possible? I realise I can simply activate it myself if required, but there might be situations where this functionality might be useful