Well, you could look at it this way. If, according to the admissions blog, "most" decisions have been posted, and 1800 people applied to various Fletcher programs, and an average of 25-30% were admitted, there would have to be rejections in there somewhere. I would not quantify "most" as a couple hundred admitted students, so there could be a good chance that in whatever system was used "a decision will be posted here when it is available" really does mean that Fletcher has yet to input a decision, it could be anything, waiting until Monday means nothing, and that Fletcher really has yet to get to us whatever the decision is. But, using the same thought process, you could also ask why Fletcher would notify the vast majority of accepted students and leave only a few left until Monday if "most" applicants were notified. It does seem, however, that Fletcher hit the early notification acceptances first with scholarship information and went down the line in some fashion...
Sigh...