Ah, but once a deadline is set, it is very hard to un-set. Apple does not exist in a vacuum, it communicates its schedules to others and huge efforts are made b

Ah, but once a deadline is set, it is very hard to un-set. Apple does not exist in a vacuum, it communicates its schedules to others and huge efforts are made by many people and companies to meet that deadline; it is not a trivial thing to change.