Call MS and see what they say - They're open today.
AFAIK, all reservation using developer points have to be done manually by a special group within MS. I'm sure that's true for the new shorter II reservations as well. Maybe your guide was mistaken. Be sure to ask for a Supervisor if the first person you talk to says that you can make the new reservations yourself online using developers' points. That really just doesn't sound right based on how they do everything else. It would be easier to believe that developers' points can't be used for those than to believe all of a sudden you can use them to make online reservations. Good luck!