The infamous $50 Walmart exclusive Spoiler Pack had the words "spoilers inside" that referred to the Netflix series we had not seen yet and Hasbro had advised we only open it after watching the Netflix show. Now I see that the advice was sound. Not because it meant that we would spoil ourselves (which is probably what they meant) but because it would only make sense once we watched the show.
In the show, Ultra Magnus dies. It is a rather brutal death at the hands of Megatron and is what makes Jetfire switch sides.
Now that we know this, the toy's deco makes much more sense. For those who do not have the spoiler pack Ultra Magnus, the toy is made up of a lot of grey plastic with colour sprayed on. Many found the deco underwhelming as it didn't really look like battle damage. That's because it is not. It is Ultra Magnus having just been killed and his colour fading, making him become grey, just as Prime did in the original 86 film. Below is an image of the toy and you will see how that interpretation makes far more sense than anything else. The inclusion of rung, along with that pink colour scheme remains unexplained.