Plans can change, the past cannot. Now, if there's breaking news however and it affect a large amount of people in a negative way, you'll notice it'll be reversed before it'll become finalized. This is something similar to that vein of thought, and IMO is why social media is important.
I'm trying to wrap my head around just what wikileaks is doing differently here, regarding BEFORE and AFTER. It would have been nice if wikileaks had told those photojournalists that the gunship was coming BEFORE they were killed, instead of posting the video of the event AFTER it happened.
Oh, wait. The Pentagon already does this: The have battle/attack plans for every country in the world! So I guess they should leak those and let people scream in outrage?
A plan is not equal to intent. And you only know intent after it happens, not before.
By the time a schedule like this is announced (even internally in the military), it's already in progress!
Not that this is a problem inherent to Wikileaks; you could use any service to communicate the same thing. I'm just giving an example of a time where publishing sensitive documents could be done ahead of time to disastrous consequences.