160rmf on 26 April 2017
The only thing that was held back in Smash 4 with the 3DS version was the character rooster, the only thing they mention that would be shared among both.
Both versions have their singularities based in it's hardware capabilities so I don't see why would be different with the Switch.
Making a new game from the scratch it would be a waste of time and resources. So a deluxe version with story mode, more fighters (new & old), more new stages, more single player modes and Wii U and 3DS content (including DLC) combined will be neat, it would feel like a new Smash game.
We reap what we sow
