Jay Thanks for addressing this! GCal now correctly reflects date clearing and dated item deletion in Legend. Thanks!
One remaining issue (of lesser importance but it would be nice) is that deleting an event in GCal is not removing the date of the item in Legend. I believe that is how it used to, and is intended to, work.
Also after I delete the event in GCal, any changes to the date of the item in Legend are not reflected in GCal. Maybe it is trying to update the corresponding GCal event but it has been deleted so it is not present in GCal?