[CaptainCrunch]

Originally Posted by Blaster86

Spoiler!

Cody was never a member of the 501st. You're thinking Rex.

True, but

Spoiler!

We know that the Empire went away from Clone troops at some point between ROTS and ANH, and that the recruit troopers weren't anywhere near as good as the Fett clones. so it would make sense for Vader to bring as many of the clones into his elite legion.

I guess the only problem would be that the Clones age at an accelerated rate. So if Rebels' happens about 15 years after order 66 most of the clones that survived would probably be in their late 50's or early 60's age wise.