That image is going to be the bane of our existence for the next few months.
It could be a new game but I feel like that might be a bit loose statement. No doubt they would be using quite a bit of Wii U assets because the timeframe from DLC onwards is ~2.5 years if the game releases in Q4 of this year.
Regardless, Inklings are there, and I guess BOTW Link might be the primary Link now (Toon Link carries on the old traditions, probably), and we're probably going to get some folks like Pyra, Spring Man and the assortments.
Either way, my gut says it's an extension of Smash for Wii U with anywhere from 6-12 new characters, and probably branded as a new title/definitive experience. rip bayo though, she's getting nerfed to the ground probably