It would also depend on how the content of the signal sent into the cable by the source component changes when the cable is disconnected, as a result of that component having nothing to talk to at the other end.
Why would it matter what the source is sending if you have disconnected it at the client? These are buffered (FIFO) systems and the audio is still playing.
The only change in 'content' is the 100% lack thereof.
Once again: What sonically changed about the audio when the cable was disconnected. What does the cable, what does mixed signal systems wrt to analog and digital ground plane mixing, have to do with the DAC playing out of buffer (that isn't going to get refilled unless the cable is plugged back in)?
A good litmus test for these multi-thousand dollar pieces of audio gear is to evaluate it blinded and start playback and see if you can hear when a friend, without cueing you in on it, has disconnected the cable. If I / you hear a clear difference I would take a pass on it personally.