Jibanyan
Chance: 40%
Sleeping on Yokai Watch for being young is dangerous. Yokai Watch hit Japan so powerfully that it punched a hole into every Japanese parent's wallet, and Nintendo's already shown it's all-too glad to push for its continued success - the number of people who went to buy Yokai Watch games was ridiculous, and anyone who wanted to do so had to buy the Nintendo system that supported it. Add to that the fact that this is Level-5 who owns them, a company milking this franchise so hard that it nabbed cross-promotions from the likes of Square Enix to the freaking Olympics. In any realistic interpretation of these things, Layton has already been cleared off of their discussion table.
What keeps Jibanyan and his franchise's ambitions in check, then, is the very fact that their ambitions are loftier than they could actually realize. After movies, crossovers, and entire merchandise stores devoted to it, Yokai Watch now stares at its own decline, a sign that they might've just been a flash in the pan after all, rather than a new and enduring IP. For a franchise to stay around in the long term, you have understand what exactly makes it so appealing to people - and Level-5's recent turnaround of the franchise into some horror knock-off suggests that maybe they don't. Sakurai would especially choose the classical fire cat if he ever made the choice, which would run counter to Level-5's current strategy of rebooting absolutely everything.
I wouldn't say its Japan-centricism is what holds it back - Sakurai included an unlocalized medieval turn-based RPG into Smash, after all. Rather, I think it's its identity as a passing fad, an eruption of popularity that now faces the threat of death if it keeps going down this path. But right now, Yokai Watch still does a heck of a lot better than most other franchises, even moreso back in 2016 when the roster was likely completed, and it's doing plenty to try claw that success back to it. Not to mention that Jibanyan has all the connections it needs to state its case, what with Nintendo and Level-5's close relationship, and can even entice the possibility of a direct confrontation between itself and the Pokemon franchise. I don't doubt that there was pressure on Sakurai from his higher-ups to consider a Jibanyan inclusion - the question becomes whether he thinks Yokai Watch's crescendo in popularity could stand in for the years of history that makes other 3rd-parties viable.
Want: 20%
The mascot of a distinct example of a successful game franchise appearing even in this day and age, Jibanyan's fairly up there in terms of moveset potential and modern relevance, trumping a good number of characters on both fronts. But his franchise's pride is its downfall, and like Digimon before it, I can't help but wonder if we'd really be honouring the games with such an inclusion, when it seems more as if the root of its success is the mass of media surrounding it.
Prediction:
Marx: 8.7%
Nominations:
Papyrus (Undertale) x5