I had a response ready - and then just deleted because I figured "why bother". But Jill's comments hit the nail on the head. Its the failure of good, professional communication.
So, today is 18th of December and you are just now responding? Should have been weeks ago, as Christmas and the New Year were always coming (unless you believe the dooms day calendar) and you had to know the vacation schedules of staff.
Going into technical reasons is all-well-and-good, but truly irrelevant to the fact that no communication was given. I work in the field and the folks don't care about the "why" for the most part, they just want it to work correctly on the date given. If I miss date, they want good communication/notice and a new date. I would have thought that aspect of the prior GD/Producer failures would have been obvious and not continued by the current team.
You could easily have avoided a lot of the issues if you had just announced what you did today a few weeks ago. We would have laughed and flamed a bit, but really we know we are lemmings and we would have moved on to other things.