I am not pessimistic. I am, in fact, every now and then accused of being to optimistic by the other forum members.
C-24 didn't take two weeks. It took a year.
I am not saying that it will take a whole year, but they won't pressure-rush this through just to make people like you and me happy. They will take a reasonable approach in implementing the rules.
Also, time is a continuum. So your 15-month-save doesn't go away if they take some weeks or some months, it would just be a 12 month save instead etc.