Super Smash Bros. fans may be hoping that Kirby Air Riders doesn't experience delays. A rumor suggests that Masahiro Sakurai only remains committed to the fighting franchise because of the racer. Since he's unlikely to have started work on a new Super Smash Bros., its release date is unclear. https://www.notebookcheck.net/Masahiro-Sakurai-developing-Kirby-Air-Riders-could-delay-Super-Smash-Bros-Switch-2-game.1045407.0.html
An all new Smash doesn't make sense at this point if it isn't even in pre-prod. Nintendo will probably just make a "Deluxe" edition for the switch 2 with even more characters and long-needed balance patches.