This one was a hit and miss for some time. A lot of people thought we would see a port of the highly successful Wii U version onto the Nintendo Switch. We think differently.
One of the main reasons why I say this is a brand new game and not a port of the Wii U version, we had seen how quickly they ported over a remake of a game. Take a look at Mario Kart 8 Deluxe. Not long after the Nintendo Switch was released we seen it ported over with new features. If they were to port over any other games, we would of seen it by now.
There wasn’t a lot of information of course, but we can expect the new Super Smash Bros. to be out in 2018. Check out the reveal here: