Update: Game Developer cite a source familiar as having told them that Halo Studios staff have “departed as a result of external contractor shifts” and that no full-time staff have been laid off. Original story below: Halo studios appear to have cut an unspecified number of staff following the release of Halo: Campaign Evolved last week. A number of contract workers at the studio have posted about their departures on LinkedIn within the past day or so. Halo Studios’ parent…