As you may or may not know, Sgt. Rock is a WWII soldier. He's always fought in WWII. The poor guy has never even gotten to leave the European theater. (It was rumored in Swamp Thing that he was transferred to the Pacific, but never confirmed.) Any attempt at a movie adaptation has always gone forward with this central idea of keeping him in his element. But budget, politics, and popularity has always been an issue, and no one believes you can make The Dirty Dozen in this day and age unless you're Quentin Tarantino. So Warner Bros has decided to bypass the drama, and put Sgt. Rock in the future. CG is cheaper than Nazis, and a nondescript soldier of the future is less problematic than an American fighting a good fight. (While no war is a good war, I do think we can all agree that fighting Nazis was a good thing.)
Nothing else is known about this storyline, so I hate to jump to a knee-jerk conclusion as to who or what Sgt. Rock will face there, or whether he will be transported to the future from WWII. But I think this is an unfortunate thing to do to a character who resides in WWII for a very specific and honorable reason. The last thing he should become is a Universal Soldier or Terminator ripoff.