In my personal opinion, the easiest way to predict what Square will choose is to look at their past business decisions. Because we know they are very strict about letting leaks get out, combine that with Nintendo themselves spreading false information among insiders and Square spreading false leaks. The whole leak and insider department is a mine field.
So in my opinion the best way to predict Square’s movements is by their past business decisions. In some ways Square can be predictable because they always choose cross promoted characters that are globally popular.
So let’s look at their recent cross promotions and see if we notice the pattern.
Cloud in Smash Wii U (Cross promotion of FF franchise and FF14)
Ardyn & Bahamut Assasins Creed Origins (Cross promotion of FF15)
Noctis Tekken 7 (Cross promotion of FF15)
Behemoth Monster Hunter World (Cross Promotion of FF14 Heavensward)
2B Soul Calibur 6 (Cross promotion of Nier Automota)
First let’s look what these have in common, no leaker as far I’m aware of sucessfully leaked that any of these were coming, they were all surprises. In the case with Cloud he was predicted by someone, not leaked. So this proves despite crossing over with different companies, Square is still very strict about leaks not getting out.
Next point the majority of these cross promotions are globally popular characters, and they are able to cross promote. They are also safe characters in that Square is not choosing characters that are not relevant. Also these characters are helping Square make the most income from cross promotion both long term and short term. It should be noted the reason the majority are FF picks is because FF is Square’s biggest and most profitable franchise. It makes sense they want to push for this as people from other games may be drawn to the FF franchise. Also if you notice once again all FF picks are globally popular and are safe picks in that they are still relevant.
Let’s look at 2B, she is owned by Platinum games and published by Square. This means in Soul Calibur 6, three companies shared profits Bandai Namco, Platinum Games & Square Enix. This means Square is willing to share profits with another company if that means they have a higher chance of cross promotion and income.
Finally all these characters come with a maximum of two-three pieces of music. Or in the case of Ardyn & Bahamut zero pieces of music.
In my opinion the real contenders for the Square pick are Geno & Sora.
Sora because he would make all three companies the most amount of income. His game would already be out when the DLC is released. Keep in mind the whole he’s not on the Nintendo Switch argument has been thrown out the window with the announcement of Joker. There are rumors Persona 5 is coming to the Nintendo Switch. They could do the same thing with Sora and announce a KH bundle coming to the Nintendo Switch, or sell them separately. Also Yoko Shimomura the KH composer is already on board in Smash as she remade Vega’s theme.
Geno, is not out of the running in my opinion. It should be noted that in leaks both of these characters were targeted. Which seems suspicious, given their high popularity. Geno brings a unknown/ wild card factor in this. He is the character that is unpredictable as he could make it in on nostalgia. He would be going against all Square business decision patterns, but they could choose him as a sign of good faith towards fans, Disney has proven many times that nostalgia sells, and if he has a secret remake of SMRPG in development it would really lean in his favor. Yoko Shimomura is also the SMRPG composer, so she could also be used here.
I could potentially see Neku or Erdrick. These seem less likely though. Neku whike globally popular and easy to get due to no other party. Might be too safe of a pick, and may not help them receive as much income as they could have with a more daring pick.
Erdrick has the whole DQ mess going on. To start DQ is not as popular in the West with 75% of DQ11 sales being made in the East. Then you Sugiyama and the whole mess that surrounds DQ music as he owns the music. Finally you don’t have three companies to deal with, but four in this case(including Nintendo) plus you have Sugiyama. That’s a lot of people to deal with. It’s possible both Nintendo & Square will choose them though. As despite a gamble, it could make DQ popular in the West, like how Smash helped Fire Emblem.