Steve is divisive and is not super big with the fanbase at large. Chief is just not wanted mostly due to the fan perception of Nintendo history mattering. To many people, Banjo is still a Nintendo character. I can safely say he heavily outperformed both without relying on fan data. He will not go to Microsoft with the intention of only grabbing the two former. In fact, I can use Geno as a great example here. When negotiating Cloud he still tried for Geno and that's how we ended up with a Mii costume. Sure he didn't manage to get both but he still tried and that's what matters here. Sakurai isn't going ignore the most of loved of the three characters and just not negotiate for them. That is why I so sure that if the other 2 make it Banjo will too. I suppose it is possible that another situation arrives where the two companies couldn't agree on terms for both but with how willing Phil is to work with Sakurai, I find it far more likely either Sakurai walks away with nothing or Banjo comes along with the bigger name. Negotiations are far more likely to just break down than Sakurai has to settle for one character. There is no real possibility we get Microsoft content and Banjo isn't a part of that deal.
You make it sound like Minecraft having content isn't a big thing that and won't do very well. You are still putting Banjo way higher than he remotely deserves to be. No, he isn't this big gun in any way. He's a very popular character from a great franchise. He is nowhere near the top of Microsoft's major IP list. Let's please stop severely overrating his chances. I can't see Sakurai walking away at all regardless of Banjo, because he isn't the only reason to ever go to Microsoft.
Also, Banjo is the Geno of that analogy. But then we already have the one problem with your analogy, there is nothing to imply Sakurai wants him in the game. At all.
Also because I forgot to mention it in my last post the thing about Geno is we don't need context about his inclusion. Geno was considered and Sakurai was willing to put in an irrelevant character from a dead franchise. Full stop. That's all we need to know. As long as Sakurai was ok with adding a 3rd party who no longer matters then why he didn't make it or for what reason he wanted Geno in the first place doesn't matter. All that matters is we do know is being a dead character doesn't disqualify a 3rd party and that's all we need to know Banjo is in play to be considered.
No, we need to know why on earth he considered Geno in the first place in Brawl to ever compared it to Banjo. If it had nothing to do with fan demand at all, then Banjo is an irrelevant point as it assumes he's a huge fan of the Bear and Bird with absolutely nothing supporting that. Him considering the characters due to the fans and dismissing them doesn't mean he wants them playable. It just means that... he's answering the fans and what they asked for. That's all it actually means at that point. Again, Banjo is as likely as James Bond was, and nothing right now changes it to our knowledge. The ballot's results are unknown and aren't a good reason to believe Banjo is some kind of lock if Sakurai wants a Microsoft character. He might not even think it's a Microsoft IP worth going for. Noting the demand exists does not mean he is going to answer the demand. This is something you have to remember. Demand will not always be enough to begin with.
There are 4 major IP's right now that are with Microsoft worth getting. Killer Instinct(relevant, gaming history, recent), Minecraft(relevant, gaming history, recent, severe popularity), Halo(relevant, gaming history, recent, fan demand), and Banjo & Kazooie(only has fan demand on their side). He could go for any of these and walk away with only 1. The reality is? Yes, it could happen. It's pointless to deny this possibility. I don't think it's likely B&K won't show up at all, but I also don't feel it's right to overrate their chances when that would set me up for extreme disappointment if it doesn't happen(mind you, I also am not a major fan of them, but I do think they are a legit choice and a viable contender. Just not on the level of the other three IP's at this point. If it was not dead, then it would be). Fulgore legitimately has an issue with fan demand, unlike Minecraft, Halo, and B&K content. But that's the only thing going against it. I don't think Fulgore will be playable. B&K are a bit low and have decent chances. In fact, I honestly think there's a good chance we'll get no playable Microsoft characters overall. Maybe some AT's or other non-playable content at best. There's just too many negotiations and unknown factors to begin with. We don't know the ballot results and to act like B&K are super high is a bad idea. And I'm someone who thinks it's their only remote chance of ever being playable right now. Doesn't mean they will even be considered for Ultimate(as they may be just outdwarfed by tons of other characters, or the fact they're currently irrelevant might be enough to keep them out. Again, we can't compare this with Geno because his reason for being wanted in Brawl is unknown. It's a fallacy to think Sakurai will consider any irrelevant character just because he considered Geno. If it's fan demand, then yes, it's comparable to Banjo. If it's not, then the comparison falls flat entirely. Maybe he simply played SMRPG and that's all it was. Has he played B&K? Possibly? Maybe he didn't, and just noted the fact they got some votes and that was it).
Do you see the issue now? You're using a lack of information and pure want instead of looking at other valid possibilities. I mean, it's fair to think it's likely Sakurai is going to go for Banjo when going to Microsoft. I agree. It's likely. But a guarantee? No. Just a valid possibility. Also, I'll make it clear that the reason I'm trying to make sure you understand this so if we only get non B&K content in(a valid possibility), you understand why it was not as much of a guarantee as you and others think it was. I don't want people to set themselves up for disappointment instead of simply accepting things might not go the way they want. And again, I must note that I think he has a decent chance of getting in, but not by himself in any way. I can't see any reason for Sakurai to ignore the highly iconic other Microsoft content, which will sell the game even more since it'll grab multiple customers besides a small set of people who played in the n64 period(as an n64 vet myself, I know for a fact that there's too many people who don't know or care about B&K, meaning he will not be the best system seller ever either. Definitely will grab a set of fans, just not as much as characters like Sonic can, or even Master Chief, who appeals to a significantly bigger fanbase beyond Nintendo fans at best).