“…why animation goes before rigging in core…”
You can learn how to Animate, using rigged models, you don’t have to know how to Rig something, in order to be able to Animate.
But, you will need to know how something is going to be animated and thus to know Animation, in order to make a useable Rig.
This will make sense, when you get to learn Rigging.
That being said, you can totally learn some basic Rigging first, to be able to pose you characters, but that would require some Armature and some Weight Painting and there would be no need for a fully functional Rig (a Rig for Posing, is a lot simpler, than a Rig for Animating).
