I definitely thing one day, they're just going to announce that they have nothing but a Smash trailer to show.
I can see Bandana Waddle Dee showing up in something like that.
But don't lose any hope, guys. Keep in mind that BWD is still by far one of the highest requested characters in Japan. It would seem pretty unfair for Sakurai to give all these characters to people in the west, then give his home country barely anything.
This is partially a reason why I feel like Dee's still got a good chance. Chrom got in due to Japanese demand, after all.
On a different note, while I don't believe Sakurai's fulfilling any quotas of any kind, I can't help but feel that Kirby so far has been kind of left in the dust while every other major franchise so far has gotten something in terms of playable characters.
Super Mario got Daisy (and may or may not get Geno).
Donkey Kong received King K. Rool (and could be getting Dixie).
The Legend of Zelda had various tweaks and changes among its characters, as well as the returning Young Link. (Also, Skull Kid and Impa as a Sheik echo are possibilities which should not be ignored.)
Metroid got both Ridley and Dark Samus.
Yoshi... uh... I guess Yarn Yoshi is possible? But to be fair I count Yoshi in the same series as Mario myself.
Star Fox got the returning Wolf.
Pokémon saw the return of Pichu, Ivysaur, and Squirtle.
Fire Emblem let Chrom in.
Animal Crossing now has Isabelle joining the Villager.
With Ultimate being quite fanservicey, I just really hope Sakurai won't pass up a character for the series he helped create, especially with how big of a deal it's become to Nintendo, with it getting at least a single game every year since 2014. (2014: Triple Deluxe, 2015: Rainbow Curse, 2016: Planet Robobot, 2017: Battle Royale, 2018: Star Allies, 2019: Extra Epic Yarn.)