https://www.gamespot.com/articles/super-smash-bros-ultimate-roster-has-all-previous-/1100-6459707/

Nintendo's upcoming Super Smash Bros. game, Super Smash Bros. Ultimate for Nintendo Switch, was finally revealed during the company's E3 2018 Direct presentation. As the company began to rattle off the roster of playable characters, there was one thing that slowly became increasingly clear: Everyone is here.

Every single character who has ever appeared in a Super Smash Bros. game--from the original 12 characters featured in the Nintendo 64 title, all the way up to the latest DLC characters made and released for Super Smash Bros. on Wii U--will be included as a playable character in Super Smash Bros. Ultimate.