My best guess for the contradiction is Michael Bay and ILM have a plenty of room to make changes as they see fit for the move but Hasbro is locked in on design of the toys by about a year from the release date. So in this case, they had to finalize the design of Devastator around May of 2008 while Bay has had all that time in between to tweak the design as much as he wants. It would be a question worth asking at the Hasbro panel at Botcon next weekend.
Supreme Devastator Bio
The ultimate Decepticon weapon has arrive on Earth and nothing will ever the same. Constructicon Devastator is the biggest robot ever - towering above Autobots and Decepticons alike. As his Vortex Grinder snaps open and glows with power, all before him quake in fear, knowing their destruction is inevitable!