This news was indeed a shock. However, I am happy there was an abdication rather than Prince Frederik taking over at the death of Q. Margrethe. Obviously, the decision was made a while ago and it makes sense for me why the Queen made the sudden changes to the title of Prince Joachim's children and then also Mary and Fred's second visit to her family and Mary's tears at her departure. I assume Mary must have told her family and close friends and realized she wouldn't be able to visit for a while more so that her Dad was not well. Hopefully, he and her siblings will be able to travel to Denmark for the day when the Proclamation will be made.
Happy retirement to Queen Margrethe and congratulations to the Crown Prince couple.