As to how this was made possible, in an interview with Kotaku, Xbox CEO Phil Spencer revealed that it is all thanks to Microsoft and Nintendo's healthy working relationship, making it easy for the duo to appear in the franchise. Lastly, Nintendo also confirmed that Banjo-Kazooie composer Grant Kirkhope will rearrange the music of the franchise for Smash Bros. Banjo-Kazooie is set for a Fall 2019 release.
Nintendo will release five DLC packs, with each pack containing one new character, one new stage, and new music tracks. The first DLC pack was Persona 5's Joker. Super Smash Bros. director Masahiro Sakurai previously revealed on a tweet that all the DLC characters for the game were decided by Nintendo and that he has the final decision if they can turn the characters chosen by Nintendo into a playable fighter. Each DLC pack cost US$5.99 and you can purchase all DLC as part of Super Smash Bros.' Fighters Pass, which cost US $24.99. All packs will be released individually until February 2020.