Last week during the latest Nintendo Direct dedicated to Super Smash Bros. Ultimate before launch next month, Director Masahiro Sakurai revealed that there would be five additional characters that appeared in the roster after the game's release to February 2020.
Super Smash Bros. Ultimate's DLC Setup is now complete. This time the election was completely released by Nintendo. I decide if we can make a fighter based on their choice, so come up with the plan.
– 桜 井 政 博 (@Sora_Sakurai) November 6, 2018
This led to the usual rampant speculation that occurs when developers announce that DLC characters are inbound, but Sora Ltd. has given some insight into the decision-making process for the remaining additions. On Twitter, Sakurai showed that Nintendo was responsible for the DLC setup, distinguishing it from how characters are selected for the launch list and that all five characters are already determined. Although there will still be many theories about which five characters from Nintendo's massive library of franchises that will make their first appearance in the Smash Bros. games, this Tweet seems to indicate that the remaining warriors will first and foremost be first-party participants and will probably not being affected by the popularity of upcoming titles in the months to be followed.
Super Smash Bros. Ultimate will land on Switch on December 7th.