Since Sakurai completed the mission of the late Satoru Iwata (who died in 2015 due to a bile duct tumor), he won't have to worry about fans wanting for new characters (such as upgrading Waluigi from Assist Trophy to playable character); HOWEVER, if Nintendo were to continue the Smash Bros. series, they'd hire ME to do it. The name of the SIXTH Smash Bros. game would be Super Smash Bros. Beyond; the following features would be added:

NEW CHARACTERS
Aelita
Odd
Ulrich
William
Yumi
Sailor Moon
Sailor Mercury
Sailor Mars
Sailor Jupiter
Sailor Venus
Sailor Uranus
Sailor Neptune
Sailor Pluto
Wreck-It Ralph
Shadow*
Silver
Shantae
Rottytops
Risky Boots
Waluigi*
Knuckles*
Izuku Midoriya
Ochako Uraraka
Katsuki Bakugo
Denki Kaminari
Eijiro Kirishima
Kyoka Jiro
Momo Yaoyorozu
Tsuyu Asui
Mina Ashido
Minoru Mineta
Shoto Todoroki
All Might
Viridi
Tetra
Shovel Knight*
Necrozma
Sceptile
Toon Zelda
Krystal*
Spring Man*
Ribbon Girl
Nia
Scorbunny
Impa
Ladybug
Cat Noir
Rena Rouge
Queen Bee
Reika Kirishima

NEW STAGES
Kadic Academy Courtyard
Kadic Academy Soccer Field
Desert Sector
Forest Sector
Ice Sector
Mountain Sector
Sector 5
UA Hero School
Fix-It Felix Jr.
Sugar Rush
Game Central Station
Hero's Duty
Litwak's Arcade
Internet Hub
Slaughter Race
Crystal Tokyo
Crossroads Junior High
Eiffel Tower
Emerald Hill Zone
Angel Island Zone
Master Emerald Altar
Death Egg
Knothole Village
Echidnapolis
Thorndyke Manor
Blue Typhoon
GUN Base
Prison Island
Station Square
Space Colony ARK
Fire Field
Death Wind
Press Garden Zone
Null Space
Inkopolis Plaza
Inkopolis Square
The Splatlands
Splatsville
Alterna
DJ Octavio's Hideout
Extra Large Battlefield (8 platforms)
Huge Battlefield (9 platforms)
Final Destination (64)
Final Destination (Melee)
Final Destination (Brawl)
Final Destination (3DS/Wii U)
Final Destination (Ultimate)
Super Mario Maker 2
BC 70,000,000
BC 65,000,000
AD 969
AD 1999
AD 4001

NEW ADVENTURE MODE
World of Light 2: Galeem's Revenge
Description
After the defeat of the two most evil enemies in Smash history (Galeem and Dahrkon), the Smashers congratulated Kirby on a job well done; a few years later, new Smashers were welcomed with open arms. In the depths of the ocean, Galeem witnessed Dahrkon getting weaker; the Demon of Darkness transferred whatever strength he had left to the Lord of Light. This made Galeem exponentially stronger; the Lord of Light rocketed out from the ocean and back into the sky. Back at Smash Mansion, one of the new Smashers felt something strange coming from the cliff; every Smasher, old and new, hurried to the said location to see what it was: Galeem, the Lord of Light, was back. Ralph, one of the new Smashers, hid in a cave and created a shield so that he wouldn't get incinerated by the searing paths of light; he waited until the dust settled. When the dust finally settled, Ralph walked through the canyon only to see a city-like fortress; he now had a mission: to free his friends and defeat Galeem once and for all. {in WoL2, you play as Ralph}

Bad ending (must awaken anywhere between 15% and 45% of all Spirits and defeat Galeem to unlock) [narrated by Yumi]
Ralph defeated Galeem, but only managed to free some of us; the rest were still Spirits. Master Hand punished him by locking him up in the Mansion's Confinement Chamber, only coming out of it for mealtimes and training; Ralph apologized to Master Hand, only for the latter to turn it down.

Good ending (must awaken anywhere between 55% and 85% of all Spirits and defeat Galeem to unlock) [narrated by Cat Noir]
Ralph defeated Galeem, but only managed to free most of us; the rest were still Spirits. Master Hand accepted Ralph's apology and was told to do some training sessions with Lucina; it was going to be pretty tough, but eventually, his training was complete.

True ending (must awaken all Spirits and defeat Galeem to unlock) [narrated by Ralph]
I did it; I defeated Galeem and freed all of my friends. As we were walking back to the Mansion, I wanted to know the lesson that we learned. That night, while I was looking out into the horizon from the cliff, Sailor Mercury sat down next to me; I asked her about the lesson that we Smashers learned. She said, "Without light, there is only darkness; without darkness, there is only light. Light and darkness are equally balanced; you can't have one without the other. That's the lesson that we Smashers have to learn." I stood up and walked back to the Mansion, with Sailor Mercury riding on my shoulder; the next day, I told the other Smashers what Sailor Mercury told me. After that, I went to my game, packed up my stuff, and went to my new home: Smash Mansion.

Tentative release date: February 25, 2033
Tentative ESRB rating: Everyone 10 and up
Consoles: Nintendo Switch 2

(*=upgraded from Assist Trophy to playable character)
[NOTE: Everything in the game would be available from the start]