Google is not flying over the area itself right? perhaps they where using source maps with some sort of license agreement and the license expired, or there was a dispute.

It seems to me that it is in the favor of Google to gather the most up-to date maps, even if they can offer them in a limited window.

I wonder if the same is true for Google Earth, since I believe that uses higher quality / different maps in a lot of area's. (don't have it so I can't check)