Yes, and the CSS is correct.  However, even with an incorrect CSS I would expect a re-order tone of some sort.  Presently the calls are just dropped after the timer expires.

This function began working when I removed the "Reversion Number" from the Directed Call Park Configuration.

I believe that is where you would you put in the number to which you would like the parked call to ring to once the timer expires, but that doesn't seem to work.  Once I removed that field the calls rang back to the extension from which they were parked.