Its not a secret that the IW engine is used in every CoD game.
IW announces it, all the game files have the same IW engine extension types (.iwi, .iwd, etc.)
You also contradict yourself when you say that MW2 and MW3 are similar to Ante, but then that all the CoD games are different when addressing me.
Also, if these problems were known in MW2, give me one good solid reason they shouldn't be able to prevent them in MW3, knowing they exist.
When a new system comes out, its broken through after people have a look at it. Think of the Death Star, the rebels weren't like, "lol blow it up by shooting down this space, easy peasy lol"
People need time to look at what they are busting though before they can just break it. Day one hacks mean that nearly zero effort was needed to bust through and a pretty obvious gap wasn't filled.