You cant buy a KTM 450 rally equivalent to that of Coma or Despres. You buy a similar bike. Probably the best bike you can buy ready for rally racing but not comparable. Engine's and suspension are both in another league.
I seriously doubt Honda have built another frame, but I could be seriously wrong. For sure they will have a longer swingarm, but you can weld on a 55mm extension to a standard swingarm. Will they change the rake of the front fork? you can do so with a set of triple clamps.
But I hope I am wrong and they have built a rally bike aorund a fully modified 450x engine.
Maybe Honda is trying to get a larger following for thier offroad bikes, they are losing ground to the european dirt bikes albeit slowly.
"If at first you dont succeed then skydiving is not for you."