Right. They'll be back where they were - with the same risk of injury that they had before. The next day they could have another career ending injury.
Rather than thinking about it as a Cyber Surgery, I prefer seeing it as a "second opinion" or a "missed diagnosis". One doctor thought it was a career ender, while in reality it was merely a minor injury.
In response to your point, though, why not give the player some time on the DL then to recoup from the "Cyber Surgery"? It won't be his whole career, but it could be as long as a year or maybe as little as a two week DL stint.