From 2008 to 2014, a Nintendo fan named Matthew Taranto created a series of webcomics centering around the Smash Bros. roster, and among these comics was a loose series (the first of which is seen above, and more of which are shown below) focusing on who the cast wanted to see in the then-upcoming Super Smash Bros. for 3DS/Wii U. Now, years later, another Smash game is on the horizon, so why not revisit the concept? To lay out some standards, I'll consider every fighter in the Wii U game, keep the voting similar to how it was in the inspiration in that I'll group series together, and I'll treat the vote as if it happened as soon as the game was revealed (so they don't even know that "Everyone is here"), keeping in mind who has already been revealed, who could still be probable, and what would be in character.
Starting with the Mario fighters (with Wario and Yoshi), I would imagine that Peach would suggest that Daisy would be in good company, to which most of the cast agrees, with a couple of exceptions. Mario would talk with Bowser about how they haven't seen Geno in ages, and that the vote could be an opportunity to reunite with an old friend. The two agree, putting all of their votes towards him, and Bowser even convinces Bowser Jr. to vote for him as well. Wario voted for Waluigi, but was sorely disappointed.
I would imagine that the Kongs would vote separately from Mario and company, and their discussion would go a little differently. Their first instinct would probably be for Dixie Kong, but they get talking about King K. Rool, and they come to the conclusion that they actually miss getting to pummel him, so he gets both of their votes in hopes of getting another rematch with the Kremling king.
Meanwhile, the Links would carry a different mentality: bring back their cut comrade, namely, Young Link. While they would attempt to communicate this desire to each other, Sheik would tell Zelda about Impa, and after some lengthy stories, the two would agree to vote for her. Ganondorf, seeing how outnumbered he was and was soon to be, would vote in desperation for "Any Zelda villain. I'm not picky."
As for the Pokémon votes, I could see them going three directions. Charizard tries to get the Pokémon trainer back, and convinces Mewtwo to do the same. Pikachu and Jigglypuff would likely try to bring back Pichu, but they wouldn't get the support of Lucario and Greninja. The two of them would end up voting for a Pokémon from Alola.
Like the BitF comic, Samus and Captain Falcon would be voting together. However, unlike the inspiration for this thought experiment, I would imagine that Samus would get two votes since she has two character slots. These votes would likely be split between Ridley and Simon Belmont. When Samus would tell good ol' Douglas about this, he might make a move of jealousy and vote Jody Summers. If Samus doesn't get two votes, which is also a believable scenario, she would only vote for Ridley, and Captain Falcon would likely vote for Samurai Goro again.
The Fire Emblem characters would be a bit of a mess. Without any hesitation, Robin and Lucina would both vote for Chrom, declaring "He'll get his chance today!" Other than them, it would be chaos. Each of the fighters suggest someone from his own game, with no one coming to any agreement. The other tables would hear shouts like "She's another sword fighter!" and "No one knows who he is!" It ends with each character voting for a different newcomer.
On the contrary, the Kirby votes would be incredibly straightforward. They all decide to vote in their friend Bandana Waddle Dee with very little deliberation (they considered Adeline, but decided that Bandana Dee would enjoy fighting more).
The Kid Icarus characters would be similarly in a consensus for who they want. I would imagine that Dark Pit would want to vote in his new commander (as of Smash for Wii U), Viridi. Pit would likely be supportive of this idea, since he was on good terms with her as of the end of Uprising. Palutena would need a bit more convincing, but I could see her supporting this idea as well.
Fox and Falco would meanwhile spend quite a while trying to find someone from their series to vote for. The two would be unsure if the rest of the team could handle Smash Bros, and almost any other character was either a villain or not noteworthy enough. Ultimately, Fox would have voted for Krystal, while Falco would decide that he'd rather have Wolf back.
Ness and Lucas would simply decide to vote for Ninten to complete the trio of protagonists from the series. There is not much else to say about it.
Little Mac, R.O.B, Mr. Game & Watch, and Duck Hunt would likely be grouped together, but they would initially struggle to find someone to vote for. This would change when R.O.B. and Game & Watch bring up the Ice Climbers. The retro quartet would agree on this notion, motioning to bring them back, unique play style and all.
The Wii Fit Trainer and the three Mii types would be grouped together. Their votes would go in the weirdest directions with no consensus. Their outlandish requests, like Goku, Sora, or Sans, will inevitably be disappointed.
The Villager and Shulk would be put at the same table, though there would be little communication between them. The former would resolve to vote for his loyal secretary Isabelle. Shulk would take more deliberation, mentally crossing off his supporting cast one by one, for reasons ranging from them being yet another sword user, and even that one was a spoiler. He would also consider the most noteworthy characters of the later games in his series, being Elma and Rex. His final decision would likely be in favor of Elma.
Finally, the third-parties would be split into two groups. The first group, consisting of Sonic, Mega Man, and Pac-Man, would be without consensus. They would each suggest a character from his own series, but since none of them can give a solid enough reason, they don't rally around anyone.
The other third-party group would be a different story. This group, consisting of the DLC characters Ryu, Cloud, and Bayonetta, would start off the same way as the previous group, suggesting characters from their own series. Cloud would then make a suggestion that the others could support: bringing back Snake. After some selling of the idea, the three of them cast their votes to bring back the missing third-party.
That covers everyone! There are many fighters that people still want to see join the roster, and with the massive history that Nintendo has, it is no surprise. Sorry about the disappearance of images halfway through; technical difficulties are of course to blame. With that being said, who would you cast your vote for, and who do you think could still appear?