Air of the North made a small comment related to this a couple months ago in the thread titled: I want to see what do you guys think: ATLA better then LOK??. He said:
Tahno I wish we had learned some about him other than he had a posy that hung out at the local pasta
restaurant. Unfortunately, since he had his bending taken from him, I would like to see Korra fix his chi and mayhaps he could join the Krew.
So, yeah. I just feel like as the Avatar it's Korra's duty to restore all the bending losses. I mean, that must have really messed people up losing a gift they had all their lives. Do you guys think it's safe to assume that she did restore everyone's bending and it just wasn't shown?