So here's a little game.
Disregard how likely you think the characters are.
Tell us how interested or satisfied you'd be with the character if included.
I'm late to answering these, and my answers are long but these seemed like fun to answer
Incineroar: Prefer Silvally, Primarina, or Decidueye for Gen 7 rep but he got in I would be happy for his fans.
Ken: He makes sense and I would be ok with him.
Isabelle: At first I really didn't see the point, but I've warmed up to the idea of her getting in .
Geno: His fans deserve it after Ridley & K. Rool, and he would be cool although I want Mallow more but he will never get the same amount of support as the fan-favorite doll.
Issac: Never played his games, but would be happy for his fans.
Monster Hunter: Don't see the point after Rathalos got revealed as a boss for the new Subspace/Adventure mode, and the monsters would make more sense as representation than the hunters.
Lloyd Irving: Played his game and enjoyed it but I don't really want him.
Dixie Kong: After K. Rool, Dixie would complete the Donkey Kong representation for me.
Impa: She makes sense and I would be ok with it.
Skull Kid: Favorite Zelda villain from favorite Zelda game, if he ends up being a playable character or a boss I would be happy.
Black Shadow: I don't play F-Zero but he deserves another rep after 4 games of being alone.
Bandana Waddle Dee: Prefer Marx, or Gooey, but if he got in I would be happy for his fans.
Ninten: He makes sense as an echo and he was the original Ness. He has his commercial design if people are so particular about him being too similar to Ness, and he could be made to be a hybrid of Ness & Lucas with his own P.K Beam as well like Chrom is a hybrid of Roy and Ike. There's no harm in adding him in, and it makes me a bit sad to see so many people disregard him because he looks too similar from a character that came after him. Most wanted echo alongside Dixie.
Diskun: Didn't know who he was, but after googling him he makes sense as a Sakurai retro pick. Would prefer Ayumi Tachibana or Prince Sable though.
Raiden: I've never played MGS but I liked Snake in brawl so I would be ok with it.
Big Boss: Same as Raiden
Shadow: He makes sense after Richter and I would be ok with him but I prefer Metal Sonic.
Elma: Never played her game but her design and fighting style looks more appealing to me than Rex, and I love Xenoblade X's soundtrack. Most wanted 1st party character after K. Rool.
Rex and Pyra: Prefer Elma over them anyday but they're guaranteed to be DLC due to their popularity, as long as Elma got in the base roster I would be ok with them.
Jeanne: It makes sense but people got salty over Bayo so it probably won't happen but I would be ok with her.
Spring Man: He might be DLC but I would be ok with him.
Wonder Red: I enjoyed his game and would be ok with him, though I think he would end up being an AT.
Thoughts if these characters make the cut?
-Agumon: Never got into Digimon but I would be ok with him.
-Amaterasu: Most wanted 3rd party, and most wanted overall. She would also come with Okami & Okamiden's soundtracks and they have some of my most favorite music ever. She has 3 types of weapons, alongside her 13 brush powers and if she got in I would never ask for anyone ever again.
-Ayumi Tachibana: Only learned about her recently due to her being planned for Melee, but she could be Smash's version of Phoenix Wright from MvC, and I would be happy for her to get in more than most of the requested and obvious choices along with Prince Sable considering Smash has most if not all of the big-hitters.
-Banjo-Kazooie: It would make me estastic to see him get in over Steve, but I would guess he's probably going to be DLC unless Sakurai worked out a good deal for Microsoft.
-Black Knight(E): People are tired of Fire Emblem reps, but I could see him happening possibly. Wouldn't care either way, I've got Roy, Corrin, and Robin to make me happy.
-Chorus Kids: Rhythm Heaven deserves their place in Smash, and they look more interesting than Karate Joe. The Gematsu leak got me interested in them and they could be cool like Duck Hunt & Ice Climbers.
-Cranky Kong: Don't see the point, but if he got in I wouldn't hate on him.
-Crash Bandicoot: I would love him to get in, but I prefer Spyro more.
-Decidueye: Prefer him over Incineroar anyday.
-Gardevoir: I would prefer Sceptile as a Hoenn rep, but I wouldn't mind her. Also that leak with her & Gothitelle is very fake.
-Glass Joe(E): He would be cool enough, just make him unique enough from Little Mac.
-Hades: Prefer Viridi, but I love his humor so I wouldn't mind. He would probably end up being a boss in the new Subspace/Adventure mode though.
-Heihachi Mishima: Unless his voice actor recorded his lines for Smash before he got in, I don't see him happening but I wouldn't mind him if he somehow got in.
-Kat & Ana: I love Wario Ware and I'm sad Ashley didn't get in, so I would be ok with them.
-Karate Joe: Prefer Chorus Kids
-King Boo: Villain from one of my favorite childhood games, he would be awesome.
-King Hippo: He could be a cool heavyweight rival for Little Mac depending on what they do with him.
-Medusa(E): Prefer Viridi
-Metal Sonic(E): Prefer him over Shadow, and I love his design and music from Sonic CD/Generations.
-Mona: Same as Kat & Ana
-Nightmare: I liked SCIV so I would be ok with Soul Calibur reps.
-Octoling(E): Most likely DLC but I would ok with them, seeing as Splatoon 2 has great music.
-Paper Mario: Grew up with TYD, SPM, and PM64. I would love him but they would probably base him on Sticker Star, Color Splash, or Paper Jam, and I don't like any recent PM games.
-Phosphora: Prefer Viridi
-Porky Minch: Prefer Ninten, and I would see him returning as a boss for the new Subspace/Adventure mode, but he was somehow playable I would be ok with it.
-Rayman: Don't really have an attachment for him, but he got in I wouldn't mind considering how unique he could be.
-Saki Amamiya: Don't know the character or game, so no opinion.
-Shantae: If Shovel Knight became an Assist Trophy, I don't see her happening. She would most like be an AT, but if she somehow got in I would be ok with her.
-Sylux: Ridley & Dark Samus seem to fill the Metroid hole Smash has been lacking, don't have an opinion on him.
-Toon Zelda: She could transform to Tetra as well, and I would be happy with her getting in.