I'll say one thing though, due to how quickly people threw together Hero = Sword Goku, I
really doubt him. Jack ain't obvious if you didn't know Joker was coming.
I still think it's him. I'm sure the dataminers are saying that to cover all bases so people don't immediately jump to conclusions based on JUST the stats. By that one definition, the wall jumping stat could also be altered. I do kinda find it funny that people are talking only about the height changing throughout development rather than literally every other stat. I don't think the height is gonna change much seeing Sakurai knows the characters he's working with. For all we know it could be like how Lucas may appear taller than Ness due to his hair, but they are still the same height. I think I also heard a theory that Hero was in development longer than the other two? Dunno. I'm rambling at this point. I think they just don't want people jumping to conclusions without any evidence is all, which I personally don't blame them. This fandom can be insufferable at times and I'm sure they don't want to get the salt patrol on their heels when the character turns out to not who everyone expects.
We've got a bit more than just the stats backing us up though. And if Brave is Mystery Character no. 70, I think I might know exactly who it is.