I mean, what else is there in the Appendices that could apply to The Hobbit? They've already added in material about the White Council taking on the Necromancer at Dol Guldur.
If I'm not mistaken, the only relevant material comes from Appendix B, aka "The Tale of Years". It's a short timeline of events during the Second, Third and Fourth Age of Middle Earth. You can find it here
and judge by yourself.
There's some additional material in the short story "Of the Rings of Power and the Third Age", but that's in the Silmarillion and as far as I know, NewLine doesn't hold the rights to it.