Even though Julia's departure was low key I liked the way it was written. Imho FC's most complex character was on a journey of peace with herself and those around her. Cole sailing off in the boat for pastures new down under was emotional, complete with 'Maggie's Theme.' However he appeared again in season 7, when Melissa went to visit Joseph in Oz. So these appearances made his 6th season farewell anticlimactic. Vicki's departure tied in with Peter's last appearance; when the two of them went to the Swiss clinic, where troubled Eric was having treatment. I feel Vicki bowing out was at the rear of the three original character's exits.
The family are gathered outside the Falcon Crest mansion, to say cheerio to Julia. Chao-Li is ready to take her to the airport. Angela and Fr. Curtis are accompanying them, (a scene from season 6, 1986 - '87):
Angela: "Father could I have given Julia the impression that she wasn't wanted here?"
Fr. Curtis: "She knows how you feel, about her."
Angela: "Can't you convince her to stay? I hate to loose her."
Fr. Curtis: "Don't you realise Julia needs forgiveness."
Angela: "But she has been forgiven."
Fr. Curtis: "Oh no! Not until she has forgiven herself and she can't do that here Angela."
Tony (who was the once upon a time winemaker's husband) kisses Julia: "Miss you already! Lance & I are going to be alright."
Julia: "I know you will. Lance!"
Lance: "Yes mom."
Julia: "I want you to work out things with your father."
Lance: "Have a nice flight mom. It's time to go. Come on!"
He links a dejected Julia, to the white Rolls Royce Silver Cloud. Julia is mentioned in conversation over the next three and half years but never returns to her family's vast valley of grapes.