I imagine it'll be a lottery, much like the GT500KRs.Why not?
137 is nothing and easy to sell direct.
They are not being spec. as it is only 37 R's, 50 Tech, and 50 Track
It would solve the problem of pissing off dealers who were told they would have at least one each year. Hell 137 is not even enough to supply each Presidents award winner with one each.
Ford would get a ton of slack for only making 137 and not making them available to the general public.