If an app is a worm or virus from the get-go, and it is sent down this “unhackable” fiber, then it will be guaranteed to work it’s tragic magic when it gets to its destination.
I believe this is more about secrecy of the data during transmission, and not so much the impact at the endpoint. For example, a new virus may go undetected on the host/endpoint, but that would be short-lived until its signature is discovered — the virus itself could not remain undetectable as its not in a quantum state on the host its been realized.