I doubt that's the case. If it were distributed by a different company in Europe vs America, I could see it, but I'm pretty sure this is going to be the same release everywhere. Probably region free.
At least we know Cameron didn't go overboard on the DVNR in the restoration process - and if the US Blu-Ray does pull a Pan's Labyrinth, it won't be because of him, it'll be because of the distributor.