Yes, you will need to butcher animals at the butcher table first, then load the raw meat into the Replimat Hopper.

The Replimat Corpse Processor is designed to work around the "butchered humanlike corpse" mood debuff by offering a more dignified method of directly converting humanoid corpses into Replimat feedstock, while also eliminating the "tainted by human meat" debuffs in meal ingredients.

On the other hand, butchering animals yields additional useful products besides meat (such as fur and leather), without the same debuffs from butchering humans. Allowing the Corpse Processor to also break down animal corpses would sidestep an otherwise-useful production chain entirely.

I also have no plans to make an auto-butcher or Repli-Butcher building.

Looks like I should update the FAQ on the GitHub wiki[github.com].