Info needed!

As youv'e probably heard, gary fisher frames break at the chainstays. A friend of mine has broken his hi-fi 3 times a the chainstays. Since GF bikes are a thing of the past, they are sending him a Trek Ex9 frame for replacement. My question is, will the fox fork for the genesis GF frame work on the Trek? I asked him about it and he asked the local trek store and they said he would not notice the difference:skep: . I just wonder because those forks are designed specifically for the GF frames.