I wonder when people will stop pretending SMRPG was some obscure game that no one knows about. It's been rereleased way more often than Banjo Kazooie. And pitting these characters against each other makes no sense. Both are boomer favorites and Geno has certainly been more demanded for Smash than Banjo has. I also wonder when people will stop thinking it's a crazy idea that a character gets added based of of fan demand, of which Geno has more of than just about any character left in the running. There's something to say about a characters case to be playable when a large part of his legacy is a massive group of people who have begged for him to be in for a decade and a half and he's consistently recognized or talked about by the game's director.
This character is basically the poster boy for smash speculation hype, but that doesn't matter because if I take a random poll on the street he isn't as recognizable to soccer mom sally. The people that own this game and the people that basically advertise for nintendo for free by streaming on twitch pretty much universally want Geno and Banjo, so add them both.
Nobody is pretending that Super Mario RPG is an obscure game. It's also been re-released as much as Banjo Kazooie has. Banjo got re-released on XBLA, backwards-compatible on Xbox One, and more specifically with Rare Replay (this version does rely upon the backwards compatible version of the Xbox One, but it counts as an inclusion just as much as anything else). Super Mario RPG has been re-released on Wii Virtual Console, Wii U virtual Console, and the SNES Classic. Both have seen playability in three different instances so it certainly hasn't "been re-released way more often than Banjo Kazooie." I don't know if more demanded than Banjo Kazooie is going to get you a lot of results. For a longer period of time? Sure. But of every fan poll I have ever seen he has outranked Geno. And while I don't love to use fan polls as anyone who reads my comment history will know, I'm not really inclined to give Geno the benefit of the doubt of poll misrepresentation when compared to Banjo. And honestly Geno's legacy specifically is the fan base because without them, he would be just another one-off. We have made him more than that by continued support. Which is absolutely great, but I think the fact he's really only got fan support and the Super Mario RPG connection going for him, he does suffer a little bit.
Also, way to strawman the hell out of the "random polling." We specifically bring up polling because the vast majority of our polls focus on extremely insulated Smash Bros communities that often see overlap and even more problematic, support groups pushing for certain votes in polls can skew results. I won't get into it again in detail, but there are major issues with polling and Geno's a character rather uniquely positioned to benefit quite possibly the most of how we conduct voluntary fan response polls in our bubbles. Super Mario RPG may be a notable game, but the question has always been how well known, and more importantly
how wanted is Geno once you escape our bubbles. And there's no easy answer for that, and likely never will be. Enough for Sakurai to comment upon him and see his inclusion as a Mii costume. But what do those numbers look like for such action and does his special interest in Geno potentially create a bias on Sakurai's part? It's worth asking those types of questions and considering how Geno may actually perform in a wider population of fans than those participating in online boards and polls, and even his appeal beyond the 1.8 million votes of the Ballot. It's not the "soccer moms on the street" you're asking about, it's the people beyond the 60,000 or whatever a poll manages, and beyond that, the 10 million people who play Smash beyond the ballot.
There's also not a "pretty much universal want for Geno." We should all know better than that after we've seen the resistance to Geno over the years. And that's going well beyond the people who just want to troll. There's quite a large anti-Geno sentiment in many of the more general threads of other locations and people who just don't want him in. So I can't really interpret his support as "universal" (Something Banjo also struggles with, though to a lesser degree).
I'm not being critical of Geno with any of this, I just think he exists somewhere on the spectrum between icon and nobody like all characters and that we should be brutally honest with him like all other characters. He really does have a wonderful fan base that's strong, but he does have some issues that will just continue to hurt his chances and that we should acknowledge. He's always been like a solid C-tier character with a strong fan base, and I think our admission of that helps us make sure that we're able to appropriately handle criticism and not be highlighted as "delusional" by the worst parts of the internet who really do dislike us and Geno.
Part of it's significance of being on the SNES Classic is, yes, they had to go through Square Enix, but they went through Square to get SMRPG instead of/without Chrono Trigger or any DQ games. For me at least, that's pretty telling of SMRPG's importance to them.
Or it's indicative of issues we don't know or Nintendo's laziness with other games. It's not like they had to choose 21 for the SNES Classic, that's just where they stopped. Maybe Nintendo knew they had to have Square and decided to work with them on the most basic games that don't require additional licensing work from other studios (Chrono Trigger and the DQ games would be cut in this instance). Maybe they do value Super Mario RPG above those since they specifically get to show off Mario as their defining character across many games and genres. We don't really know a lot behind the decision making of the SNES Classic, and all of their stuff surrounding these plug and play consoles doesn't really paint a picture of significant effort put behind those systems since they were designed to stall in Nintendo's transition between consoles.