I'm not going to tell you not to use it. I am sure you will be just fine with proper bullet placement.
But it was built specifically for deer.
If you go to this page at the Federal Website and use the menu at the top called "Find the Right Ammunition" you can see if they recommend any Fusion for that caliber for elk.
Interestingly, Federal has started recommending the 6.5x55 Fusion for elk and moose sized game.
I suspect marketing reasons are why it is a "deer bullet" There are ALOT of deer hunters.