I swear Smash is getting crazier by the second. All these characters. (And there's rumors floating that there might even be more on the way)
I just hope they bring back Subspace Emissary.
There are gonna be more, Sakurai literally said he was gonna reveal all characters before launch and that you should be on the look out for more announcements later.
It's never coming back because Sakurai hates YouTube. True story.
Something like Melee's Adventure Mode, or like Subspace Emissary with minimal cutscenes, would probably be possible though. Have the gameplay of Subspace Emissary without the actual-effort story.
Subspace Emissary is one reason Brawl remains my favorite in the series. Smash will always be about multiplayer but it was nice to have a decent solo campaign as well.