Halo: The Master Chief Collection arrives on Xbox One November 11, so Microsoft wanted to give you a taste of what's new with Halo 2 Anniversary by releasing a launch trailer.
Yes. A launch trailer two or so weeks early. I told you this was becoming a "thing".
Granted, it's not for the entire collection, just the Halo 2 portion. Still. It will drum up extra interested in the long run.