Your active characters animations tend to stay in the animation cache once they've been loaded, so unless your characters animations are massive (large file-sizes, canvas sizes, lots of frames, etc) there's probably not much point in pre-loading them...
Now, depending on who's playing on your game & the specs of their machine, they might end up with animations loading smoothly on first play or if they are using a potato machine with regular hdd they might get a little bit of jerkiness the first time an animation is played, but usually it's only for a brief second then it should play just fine. Also depends on game resolution & various other factors.
P.S: I recommend converting your images / animations to webp format. They will decrease required hdd space for your game & decrease loading times of each scene, image & animation overall.
Find out more about webp here