"Okay fine but What does Geno have that Erdrick doesn't?"
Three Words: In-Game Evidence. With Piranha Plant joining so too did a ton of SMRPG references being Smilax in the Palutena guidence, Piranha Plant's Classic Mode being a SMRPG reference, even earlier with Geno & Mallow being Spirits, one of the new Bowser themes having a bit from SMRPG, Etc.
Even outside of Ultimate there's also a SMRPG Reference in Yoshi's Crafted World and also The Tweet
by Nintendo, The
Trivia Question with Smash being referenced in the beginning of the game, the Smash 4 Mii Costume, the Super Mario Kun Story, Etc. which is a very big contrast to a Decade ago when Nintendo refused to even mention SMRPG.
I'm not claiming to say that this means Geno will be in Smash but it at least shows that Nintendo realizes SMRPG has a very big and Strong cult following
inside and outside of Smash.
So Nintendo Knows but does Sakurai? he without a shadow of a doubt knows of Geno's Popularity as he stated he added the Geno Mii Costume cause of his Popularity Also cause he wanted Geno in Brawl and likely wanted him in Sm4sh but it didn't pan out within Smash 4. He Saw the move-set potential within Geno and wanted him so he is likely a fan of his. this isn't speculation you can specifically see him
State he wanted Geno here.
Even Square-Enix knows Geno is Popular cause they put Geno on the list instead of some huge and Iconic Character like Lara Croft/They "leaked" Geno over Lara that proves that at the very least they know Geno is popular and heavily requested for Smash.
So All Parties know Geno is Popular and Polar's NoA contact has heard Geno mumblings around NoA. With Every Party Knowing of his Popularity. Sakurai wanting him for a Decade at this point plus Sakurai adding Fan Favorites I think Nintendo can do Sakurai a Solid and add Geno unless something happens and Square begins to throw a tantrum I see why not. Every Party involved know Geno is Popular, Geno fits within Sakurai's choice of adding fan favorites this time around and Sakurai even wanted Geno and he doesn't seem to be the kind of person who would give up easily. Those things are massive points towards Geno.
"Okay but Geno doesn't fit as DLC"
I disagree with that, From what I've gathered most people seem to think that Nintendo will add Characters that appeal to people who might not have bought Smash yet but here's the thing in my opinion it makes more sense for Nintendo to focus on adding Fan Favorites or Characters that will appeal to both audiences/a Mix of both.
As if you focus on people who haven't bought Smash yet there's no guarantee that those people will buy Smash + the Fighter's Pass as that would be
75 Dollars right there. Some might not even HAVE a Switch so they would have to buy a 300$ Console + a 60$ game + a 25$ DLC Season that rounds up to 375$ just for one game and DLC I heavily doubt People would do that Meanwhile if you do a blend of both or focus on your core audience you'd have GUARANTEED Sales instead of "Let's hope they buy our stuff and hope our core audience like the DLC" I for one will likely skip the DLC if Geno/Banjo aren't in so I'm sure some are like that for their characters.
Your entire Core Audience being guaranteed to buy the DLC or Appealing to people who might not have bought Smash Ultimate or even a Switch, I think it would make more sense for them to do the first and mix in a few DLC characters that also appeal to other fanbases, Geno would appeal to your core audience.
Even then let's say Sakurai did in fact push for Geno in Base Game they could be withholding Geno for DLC cause of Square prioritizing Money more than
playing Nice.
Even Brave's Stats fit Geno with the apparent Short Zoner playstyle, The Sliding, The Wide Shield Size, Etc. Brave just feels like Geno to me, it feels like
what Geno would feel like and play like. Short Zoner fits Geno's Description perfectly with him being slightly shorter than Mario being accurate to Geno's
size and Geno obviously being a Zoner. The sliding cause Geno is Wooden and Wood has a lot of traction. The Wide Shield Size being cause maybe Geno's Cape is flowing outwards making the shield size bigger.
While DQ isn't as complicated as we initially thought Nintendo and Sakurai already have the rights to Geno and supposedly SMRPG so why go out and go through Square-enix and Toriyama when you have a Fan Favorite Character right there one that people have been requesting since Brawl at the latest! People have been wanting Geno for a Decade and they have the right to Geno and Super Mario RPG so why not use them? Not even Nintendo is that dumb. They HAVE to know what they have right in front of them and how important Geno is to a decent size of the Smash fanbase. It is a fact at this point that they have the rights to SMRPG for Smash Use.
In-Game evidence, Reputable NoA contacts saying Geno, All Parties knowing Geno is Popular, References inside and outside of Smash Ultimate, Geno fitting in as DLC, Brave's Stats, They already have the Rights, Etc. There ARE things going for Geno.