I may be jumping the gun with this comment, but I speculate that this game with have a lot more third-party love than its predecessors (and not just from Bamco either).
In previous years, Nintendo has always focused on their first-party games and whatnot at every event they held. Towards the decline of the Wii, and the rise of the WiiU, they seemed to have shifted their focus over to third-party developers. Their first-party games were actually on the back-burner for their E3 press conference. With each Smash game being iconic of it's system both metaphorically (SSB1 being a hidden gem with kinks that exploded in popularity like the N64, SSBM being wildly popular then fizzling into a niche like the GCN, and SSBB being the hated step-child of the family like the Wii) and literally (best example I could think of would be SSBB falling on the casual side of the video game spectrum while dipping its toes in the third-party, just like the Wii).
With all that said, I think it would be a logical conclusion that this game would be a ploy to draw back in some of the competitive scene alongside lots of third-party love, much like the WiiU itself. It also helps that Bamco has connections everywhere