Terminally-ill was awarded a black belt, then recovers

I recently heard a story about a white belt who used to train at my gym years before I joined. He was diagnosed with cancer and doctors gave him a few months. He tells coach he'd love to get his blue belt before kicking the bucket. Coach, out of generosity, awards him a black belt. Story tells it was a super emotional moment for everyone.

Turns out, guy made it against all odds and defeated cancer, which everyone was super glad for.

He eventually stopped training at my gym and his whereabouts are unknown for me; I don't know if he kept training somewhere else or just quit, but now he holds a black belt in BJJ nonetheless.

Whether he kept training or not, I'm wondering: what now? I know these were really special circumstances and all he wanted was a blue belt, but what was he supposed to do from then on? Should he keep and wear the black belt? What if he wants to compete? I'd like to read your thoughts on this.