The answer is easy - CIS wants to show progress in backlog reduction.
CIS has for a long time had a backlog in AOS cases. Part of CIS service center directors' job is to reduce the backlog. Don Neufeld had a perfect plan, one that's supposed to keep him employed for a longer time than he deserves - backlog will be reduced to 6 months by the end of September. However, that's not easy since the cases had been piling up for a long long time. Therefore, he concluded that if he can't show real progress, he'll show imaginary progress. Hence the bogus JIT.
Not to say that they are now approving at a faster pace, that's also happening. Someone once made an Excel-based "when will your case be approved" calculator, based on Kashmir's data I think. The dates for WAC03001 were years in the future. They did speed up, obviously.