This specific leak came about in October, and was rumored to be a piece of initial marketing for Super Smash Bros. Ultimate. At the bottom of the picture is the entire rumored cast of Ultimate characters. Those in the picture that had yet been confirmed were Shadow, Isaac, Ken, Mach Rider, Geno, Chorus Kids, and Banjo-Kazooie.
Surprisingly, there may be some truth to this leak because Ken was actually revealed in the latest Nintendo Direct on Thursday. Since Piranha Plant was also announced then, but as downloadable content, the rest of the characters that get revealed for Smash Ultimate (if there are any) will likely be DLC as well.
If this leak is actually legitimate, then that's bad news for Waluigi fans, as he is nowhere to be seen in the picture. In a separate leak, it was rumored that
Smash Ultimate releases Dec. 7, so there's plenty more time for Nintendo to have another Direct and reveal some more information. But even if Nintendo doesn't reveal any new characters before Ultimate releases, there's always the chance for DLC characters to be released later in the game's lifetime.
Photo courtesy of Nintendo and LivingDeadSuperstar