You have read that chart correctly, and as long as the chart is correct it appears that the 2014 model year will only be 8 months long.
There could be many reasons for this:
a. Ford is running out of parts for the current body style and features of the Super Duty as we know it, so rather than manufacture more parts for a limited number of vehicles, they have decided to just make the change over earlier in the year.
b. IF, and that is an IF, there are major changes in the Super Duty, Ford may fear that once information about the new and improved Super Duty is public, people will not order a 2014 and wait for a new 2015. So to avoid a significant lull in truck sales they might just want to make the change over quickly.
c. Their may be some change/improvement in the 2015 Super Duty Truck that Ford wants to be the first ones to announce something.
There could be any number of reasons, I personally think it is more along the lines of "a" . Truck sales have been better than expected.