Maybe I'm alone on this, and maybe this sounds a bit ungrateful, but I have a couple hopes of what also does and doesn't come with characters. For example, I don't want a Geno Mii to come with any of my most wanteds (Bandana Dee, Reimu, etc.) because they're either too niche or already somewhat divisive, and a bombshell like that could seriously tarnish their image, and that wouldn't be good at all. They'll already have to deal with the "Nobody asked for this!!1/Literally who?/lol hat goomba" jabs; Crushing people's hopes would just be an added kick in the teeth.
If we get a Geno Costume, it'll have to come with someone who can take it for the team, so to speak. Someone like Doomguy, Dante, or Crash, who would soften the blow a little with some fandom overlap. Instead of going "We were ROBBED!", we'd just get memes about how one sacrificed themselves for the other.
On that note, if we get Reimu I'm half-hoping it will be a Hero/Banjo situation, where we get a Western indie fan-favorite like Shantae or the Knight/Hornet (Or Steve?, if he still counts), so people don't feel too jilted about an "Anime nobody shill pick."