AMG Jack Johnson

I was poking around Allmusic.com and found that they already have a review (a very positive one) of the upcoming Complete Jack Johnson Sessions box from Columbia. They have the release date as 3 September as opposed to 30 September for everyone else. What gives? I've never seen AMG publish a review before an album was released. Normally they take a few weeks to get a review up after the release. Zach