If you're using a company's IP, it's the company's call in the end to allow you to use it or not. If a company thinks they can make a ton of profit off merchandising (as I think would be the case with Destiny) I doubt they would allow anyone to use their copyrighted IP in any way. Because then it opens the floodgates. Original art that isn't a carbon copy is a different story (like the claptrap example), but if it's a specific logo or design you see in the game, you're probably gonna get shut down.