Is there a canon explanation for what happened to all the clones inbetween ROTS and Rebels? I still don't think there is any good reason for the Empire to stop using Clones. They are more dedicated and can be genetically programmed with subconscious orders that can't be disobeyed (Order 66). They can go from an infant to adult in half the time and they live to fight. And a clone army isn't dependent on recruitment nor conscription. I just can't see Sidious ditching his clones no matter how prejudiced he is against non-humans.