Sounds as if they are setting up everything in the Godzilla 2014 Universe which includes intro of new as well as old giant monsters, so I'd guess that the Kong that gets introduced in the Skull Island movie is some new gigantic and possibly mutant form of ape, rather than the "original" 25 feet gorilla. That's the only way they could reasonably do it IMO.
Back in the 90's, there was an animated series called Kong. This Kong was huge. Kong had a human friend who had an electronic link to him. The human called him bro. I wonder if Kong: Skull Island will be set in the 30's. If it is, Godzilla will be like the Godzilla in Godzilla Vs King Ghidorah in the WW2 timeline before the nuclear testing in the Pacific islands of Bikini and Enewetok. That would work. If it is set in the present, I don't know. Gorillas and the subject of mutation does not sound convincingly feasible. If set in the 30's, the two would be evenly matched because Godzilla will not have his signature heat ray.
The next Godzilla film, I think, will establish that Mothra will have a link to Ford Brody since he had Mothra as a pet.