I honestly don't expect BWD as DLC for a number of reasons:
-He was an enhanced spirit in Ultimate which means they basically see him like a Pokemon evolution, not the strawman "hat Goomba" argument but honestly sort of insinuating it.
-Good ol' Sakurai bias. Kirby Super Star and Kirby's Air Ride were once again the Kirby games that got the most new content in Smash Ultimate, made even more notable when you realize Masked Dedede and Galacta Knight debuted in Kirby Superstar Ultra. Sakurai barely acknowledges Kirby games that he wasn't personally involved in and BWD wasn't important until Return to Dreamland.
-Nintendo's treatment of Dixie and especially Toad over the years in Smash. Toad has appeared in more games than even Luigi, Peach, and Bowser and has been the star of several games but still can't reach the echleon of Smash fighters.
The character offers a unique moveset right out of the box and definitely has a notable prescence in modern Kirby but, again, how does this set him aside from Toad and Dixie? Toad's the biggie because he has 30+ years of history and 100+ game appearances including multiple starring roles. He's like the penultimate side character but regularly rejected. I honestly don't see BWD getting in before Toad, especially if Toad's Captain Toad persona sticks.
There's other doubts that I have too, like music and a stage. BWD doesn't have a stage in canon that's specifically credited to him and Sakurai's stage selections have all come from Kirby's Dreamland and Super Star. Music is all but the same. BWD doesn't have any specific themes attributed to him and, once again, all the new remixes in this game were from Kirby's Dreamland, Superstar, and Air Ride. If they weren't able to justify a specific stage for K. Rool or even Bowser, I seriously doubt they'd do it for BWD.
All in all, not a bad character and I understand the appeal but I feel like the best case scenario is that he's considered for the base roster for the next game.