Not a leak, but a very minor detail I've noticed about the victory screen/animation...
If you win in team in Ultimate, then both characters (depends on how many players in your team) now do the victory animation. While in Smash 4, only the best character did the victory animation, and others stared blankly.
It’d probably just be unnecessary work, but it’d be really cool if certain team-ups of chaacters had special team victory animations.
Chrom and Robin, and Chrom and Lucina: they can do some pose together, and in the latters’ case, holding their Falchions together.
Kirby and Meta Knight: Meta is trying to act all stoic while Kirby is jumping up and dancing, and Kirby tries to cheer him up.
Kirby and Dedede: Same thing but Dedede is trying to act like he hates Kirby and looking away from him, only for Kirby start tugging on his cape.
Mario and Peach: Mario doing a little dance, then Peach kisses him on cheek and he gets all flustered
Mario and Yoshi: Mario rides around on Yoshi’s back for a bit
Wario and literally anyone else I don’t care: The first character stars a victory animation, then Wario runs over him/her on his bike and steals the spotlight
The possibilities are endless, especially when you consider cross-series ones like Link and Cloud, Mario and Sonic, Kirby and Jigglypuff, and various combinations of the villains.