If you decline, you are not reboarded. I have never heard of anyone receiving a Type 7 and than later being upgraded to a Type 1. The only upgrade I know you can do is converting a 4yr Type 7 to a 3 yr Type 2.
Additionally, unless this yr is different, if you are told you will be reboarded that equates to you going to the very last board in March. You will have to wait it out for many many months before receiving any decision. It is not like the old system when they would re-evaluate you at each board and you could find out earlier. This system is you wait until the very last board and are re-evaluated at that time.