Double posting, but just pointing out that a lot of victory themes have changed.
Ridley's now is the same as Samus', but in a more negative tone to it.
Lucina's (and presumably Robin and Chrom) is now an arrangement of the first few notes of Id Purpose.
Pokemon's is the same, just made shorter. Same goes with Ice Climbers.
And apparently, according to the wiki, Corrin's is now something with Lost in thoughts all alone and EarthBound has a completely new theme based on the eight melodies.
Sure leaves a lot to speculate. Will Ike's or Roy's themes also be changed to something that matches their respective FE games? What about Star Fox? Will they change it to be something to do with Star Fox Zero, since the characters' designs are also based on that game?