When Mercy restored Genji, she could gave him a normal body but she went the extra mile and turned him a cyber ninja. I guess the idea was to make him able to do whatever he did before, but better.
So she won't be turning other people in cyberninjas… no, no, no… they would be cyber-SOMETHING else. Cybertanks, cyberwaifus or cyberBBQs if she even upgrades Roadhog.