I would think the whole thing about Japan would be a big issue but I think ultimate has shown us that Sakurai or Nintendo were more open with non Japanese characters also club Penguin did have 3 games exclusively on Nintendo consoles
Non-Japanese characters who were still successful in Japan. Characters that are basically non-entities in Japan are going to have a much harder go.
And yes Club Penguin did have appearances on Nintendo consoles, but those games were spin-offs never localized in Japan.
I do not think being a discounted game would decided a fate that the characters can’t be in smash but as long as it gets supported by the community then certainly there is a chance
...but Club Penguin isn't a supported candidate by any notable measure. And even if it was, it's hard enough for actually supported characters with almost exclusively western standing to get in.
regarding popularity between Kingdom hearts and Club Penguin in a worldwide scale way more have played club Penguin than kingdom hearts due to the fact it had more than 330 million users in it and that’s way bigger number than people who played kingdom hearts but I do agree kingdom hearts is the more popular in Japan
Again you've got to look at it through the lens of the qualities that matter to Smash. Club Penguin was big, but so is GTA, so is Call of Duty, so is WoW. But these aren't necessarily the games Smash goes for, and hence are also not highly expected.
I could definitely say that both banjo and club Penguin do have a lot of fans but I am not sure what kind of comparison you mean but if you mean smash demands then yeah banjo was top ballout pick due to Phil spencer speaking out about it that made banjo fanbase wake up and vote for him so much after most of them thought it was impossible pick
I mean that saying both Club Penguin and Banjo being "dead" is basically the only thing they have in common, and using the latter as justification for the former overlooks all the actual reasons Banjo had Smash-based popularity and got included which Club Penguin lacks.
regarding if it’s going to be a fan favorite or not it’s important to note that so many people do miss that game just like people misses banjo and that game was recreated multiple times due to that and it still does have a community and a lot of fans and pretty sure Disney is aware of that going on after the game shut down
But saying it could be a fan favorite means nothing so long as it isn't. If it becomes that one day then it will be. Until it is, you can't use that as a point. Right now, and for the foreseeable future, it isn't. Not just that, it has barely any requests. Yeah, it still has fans, but I bet it used to have more when it was active, and back then it still wasn't a big request.
Not every popular series in gaming translates to a popular series for Smash.
The only thing I can imagine that would change that would be to get a character of a comparable background included, and then having the fanbase look to similar series. But that's not going to happen now when we're not getting characters.