Now we see through a glass, darkly...
- Apr 5, 2016
Without any inside information on Canon's logistics, I tend to believe it's already too late to make even firmware changes, if they're going to announce it in September and have it actually available soon after that. An updated firmware could be published and made downloadable at the same time, but by now there must already be cameras in boxes waiting to be shipped and their firmware obviously cannot be changed any more.
I also agree that the camera in the hands of testers now must have essentially final firmware. I can just barely imagine Canon doing a custom tester firmware with no other changes than fake exif data for the resolution, but even that is really stretching it.
So I guess the resolution is indeed 6000x4000 pixels. Which presumably means 4K video will be cropped, 1.04x with oversampling from 5760 pixel width (6K) or 1.56x raw.
I must, however, admit a small voice in my head telling me that those exif reports are apparently only based on a chrome plugin, which may not be reliable...
Unless it has recently changed, Canon doesn't ship anything from Japan in retail boxes. That's done at the regional level where locally sourced boxes, printed materials, etc. are combined with other products coming from other sources (camera straps, batteries, chargers, etc., which, even if made in Japan, are from different plants and shipped to the regionals separately). They're shipped in bulk packaging from the camera or lens factories to the regionals throughout the world.
In the past, firmware has been known to have been updated by staff at the regionals prior to placing camera bodies in retail packaging.