Another problem that I think people are missing is the fact that the "Duck Hunt" character portrait implies that the Dog and the Duck are a team, both being equally important to the team-up. And as pointed out before, the dog actually has a name, so if the dog WAS the only major part of the character, they'd just call the character "Mr. Peepers" rather than "Duck Hunt", which implies a team. This has been done with Olimar, who is just named after himself in-game, and his CSS icon doesn't display the Pikmin since they are ammunition rather than characters that co-operate with him. But the CSS icon on the top screen only shows the dog. Yet, Rosalina & Luma both appear in their CSS icon (which is consistent with their official CSS icon in the Wii U version, as we've seen in the demo build), since both Rosalina & Luma are equally integral parts of the pairing and are literally two different characters just made to work together. The other team-based characters, Ice Climbers, were also both visible in their portrait in Brawl too.
So essentially, we have only had two team-based characters in the history of the franchise, and both are named in a way that indicates they are a team, and the CSS icons for them depict both characters in the pair. However, "Duck Hunt" implies a team-up too, yet only portrays the assumed "base" character in the CSS icon (much like how Rosalina and Popo are the "base" character in their respective pairs). Why is that the case?
And I don't see renders that LOOK "official and new" to be any evidence, since the photos are so blurry and often have light covering half of these renders, which would conveniently cover up any photoshopping/modelling blunders. And even then, we can spot some problems with them (is it just me or does Shulk's hair in his render look less detailed than the other realistic human renders, like Robin?).
I think this news post was definitely made pre-maturely, since as soon as it was made, everyone could tear it apart anyway. In the future, wait until people have gotten the chance to thoroughly analyse it first.