To me, the 5 most likely aren;t this hard to guess because I have already built my logic on how I evaluate characters. It;s really guys a matter of priorities, all of them pretty much has very similar factors that goes for them, it jsut varies by levels.
1: KKR: clearly self explanatory, I use him a lot as examples in my argument for a reason: he;s just currently the best compromise. One of the most if not the msot popular everywhere, got a reputation for this, has very strong moveset potential that allows him to distinguish himself from the roster in an interesting way, but MAINLY what is making this choice so good is all this is coupled with the relevance of what he would reflect. To me, this character has been proven to be quite important in its series and with how much popular it is, this is true despite the fact that lately, he seems forgotten in their games. Which is why I think he;s the msot likely, but very far from certain, what hurts him the most is how he doesn;t seems that much important in dkc lately. I think his popularity does cancel this out, but it still heavilly affect how known he is. I couldn't find a better compromise of pros and cons, to me, if I had one newcomer only, it would be him most likely.
2: Paper Mario: the gap between 2 and 3 are very close.....so close that tbh, it;s extremely debatable. it;s basically take kkr, but on a lesser level without the recency problem. He;s less popular, he would reflect something that many people with very good reasons would judge a lot more optional, but tbh, we reached a point when even of how optional it is, the roster becomes so big that they become int he front line after a while. His potential is pretty much underrated, it's not necessarily better or the best as this is highly subjective, but it is definetely NOT reflecting what he looks like. He is popular, decently, he has relevance, decently considering it's more a side subset of mario, but to have that much potential coupled with this, it;s basically a slightly more than decent addition that I saw a lot of people underrate him to being redundancy. To me, he has decent chance because he would come after kkr.....except if you consider the number 3.
3: Isaac: ok you will start to see a pattern, imagine kkr, but slightly less popular in US, a lot less popular in JP and his subset is a bit less "important" (using quote because it's subjective, it SEEMS to be for me, but it might vary for you). To me, his series wasn;t THAT much important in the first place (at least compared to dkc, but I weould say more than Paper Mario), it recently got so silent that it would go a lot more down. Couple this with his lack of decent popularity in JP, this is why I put him under paper mario because the truth is this: their potential are honestly very close in terms of uniqueness. It really comes down to demand and how worth the demand is, it really comes that close to have these factors take more improtance than usual.
4: Bandanna Dee: going tbh, it;s really the most unsure guess I had, but it only goes from what I heard which tbh, I should be checking more if I really wanted to be sure. Basically, again, same thing, less popular than isaac and paper mario, but the rest sounds neat. What he woudl reflect has been lately proved to be important (he apparently got his own name and stuff), he's apparently (again, didn;t do research) considered important in its series and well at this point, I would consider....quite popular. tbh, I really don;t hear his name that much, but ler's just say it;s in good standing. I am questioning a full moveset with it spear, but that;s honestly not breaking the whole thing, it can still be decently unique. Though, i think you got why I put him 4, it's not reaching that up there as I thoguht it would be to have more priority.
5: inklings: seriously, I really don;t think they are likely, not even decent chances, but it;s the last character that I think can have enough priority to have an ok chances for this game as dlc (especially considering how limited the slots seems to be). Recently, this character became really popular, the game proved to be loved, but the problem is it would kinds need to pass the test of time. And this is why I think it;s not likely now: I have to see how it goes more. Because the game they released has this in particular, it's a long time release, they wil add stuff as it goes and this might show how nintendo care to support them. So far, it has a solid base, but we just didn't see them that much in time to think for me that they are likely NOW. And I don;t really think the ballot is going to change this NOW. I keep saying now because I think it wil change, for better or for worse, that I can;t tell, leaning towards better given how it;s going now.
There you have it. To me, it;s going to come down in the 3 most likely if you consider that I expect 2-3 slots, as for wolf.....tbh, I'm iffy given the circumstances.....I don;t want to elaborate, it's all deduction.