Fun fact: they spent quite a while working on a segmented 3D animation system for all the sprites. Every sprite is split up into segments, and then those segments are positioned in 3D space depending on the camera angle. They can even independently move each part of a character, like a leg, without having to create an entirely new sprite just for one frame.
This is 3 years old at this point, but this should give a good idea of how the new animation system works!