So, I guess it's time to finally give you guys my reasons for why I don't think Steve is in the base game, despite the "leaks". Yeah, it's time based more than anything else but there's more to it than just that.
The easiest and most telling part of him not coming in, the release date. Minecraft: Wii U Edition was the first instance of Minecraft on a Nintendo console. It was announced on December 7th, 2015 and released on December 17th 2015. Now you might say this could be seen as a boon to the character because this was the time where the game was probably in the limelight. However, we don't really know what DAY the project plan for Ultimate was finalized. Closer to the beginning of the month? Right at the end? We don't know but it's safe to say that the plan was at least being worked out the month prior at the least. Which means Minecraft missed its chance in the planning stage.
What else? Well, same thing. Minecraft missed the Ballot phase. While everyone was hyping up Banjo, Isaac, K. Rool, Ridley, Shantae, Bomberman, you name it, Minecraft was absent from Nintendo entirely. Sure, there might've been the kids who voted for Steve en masse but even then would Sakurai have taken those requests seriously? The game wasn't even on a Nintendo console at the time of the Ballot ending and the Project Plan starting. Oh, but appearing on a Nintendo console is a fan made rule I hear you say. Well no, it's not. Even Sakurai admitted to it being a part of why he felt comfortable with choosing Cloud.
https://sourcegaming.info/2016/02/23/nintendo-dream-interview-with-sakurai-part-2/
Thanks,
@PushDustIn.
So, if Steve wasn't on a Nintendo Console during the timing of the project plan it's likely he wasn't considered.
Lastly, the popularity of Minecraft in Japan is apparently not as big of a deal as here. From one of the interviews with Miyamoto and Takahashi by Kotaku:
https://sourcegaming.info/2016/02/23/nintendo-dream-interview-with-sakurai-part-2/
It's highly unlikely that the Wii U release made the game any more popular over there, especially considering the Wii U being, well, the Wii U. The 3DS Edition? We can talk about that, but that version wasn't released till this time LAST YEAR. The Switch Edition? Well that didn't released till earlier this year. The only saving grace to this is probably the Playstation Vita Edition which released in 2014. Vita was all the rage then so I could see it gaining traction from that but I have no proof.
I don't think a character from Minecraft is in the books for the base roster guys. Nothing lines up. Leakers can leak all they want and, yeah, maybe we get a Steve Assist Trophy but as a character, I think we are just not getting it. MAYBE, DLC. Maybe.