King Kong does not make much sense as a replacement for Terminator 2: 3D as that is situated in the Hollywood set. It would be a serious disappointment to see Universal, which has pushed the bar of themed entertainment, completely toss it aside and shove a story so associated with New York into Hollywood.
This is the same park that put The Mummy and Twister in New York. I think they're working with an "It's all just a backlot anyway" attitude at this point.
With that said, I haven't heard any reputable source say anything about a Kong attraction. There was a rumor a couple years ago of Kong replacing Disaster, but obviously nothing ever came of that.