Black Shadow
Chance: 3% - F-Zero's deader than disco, and it's not looking like it's coming back anytime soon. Black Shadow's only really an option in people's minds because of the fan idea that Ganondorf should get a new moveset while Black Shadow inherit the old one, keeping both intact. Not only has the moveset inheritance idea never happened before in Smash Bros., Sakurai seems to have 0 problems with Dorf's current Smash incarnation and will likely leave him be.
Want: 70% - And it's a shame too. I know it'd never happen, but it'd be much more fitting to me for Cap's dark heavy clone to be from his own franchise, rather than the big bad of the Zelda series. It'd give both Zelda and F-Zero a "newcomer", fix Ganondorf's less-than-ideal moveset, and keep the playstyle around for those who love it. It feels like a win-win to me, but unless there's suddenly a resurgence of the F-Zero franchise, not much is going to change. If we're talking as a unique newcomer though, drop my points by about 30%, as I'd much prefer Falcon's OG Rival Samurai Goroh to show up with a new moveset over Black Shadow.
Marth and Roy English V/A's
Chance: 40% - There's a non-ignorable chance of this happening unfortunately. As pointed out by Opossum and others, Marth and Roy have been speaking English for a while, and it'd probably not be difficult to track down their Heroes VA's and put em in a Smash booth. However, Marth already had an English voice back before Smash 4 and he was left Japanese, and plenty of characters' voices have been left untouched between games before, so I think it's slightly more likely they'll just leave it as-is.
Want: 0% - No. Thanks. Marth and Roy speaking English in Heroes and other places has always felt alien to me, like I'm hearing illegal audio the government doesn't want me to hear. A toggle for it? Sure, Street Fighter and Marvel vs. Capcom have done it before, I'll leave em on Japanese and never touch that menu again. But a permanent unrevertable change? I'll pass.
Predictions
Lycanroc: 23.45% - The dorito dog has, fittingly, an underdog's shot at making the roster, but Decidueye feels much more likely to take the coveted Pokemon spot, and I don't see us getting two new Pokemon. Being a quadruped without the cartooniness of Duck Hunt or Ivysaur's handy dandy prehensile vines would make a lot of it's animations difficult as well.
Nominations
Scorpion x 5