It’s ridiculous. I’ve never seen of known of such a thing from the time I was in the Army, and the Mrs is a Marine brat who says two officers would always come in a black sedan.
From Wikipedia, Hal Moore’s wife helped get the practice ended.
“The Ia Drang Campaign was the first major ground engagement involving U.S forces in Vietnam. The Army had not yet set up an adequate system of notifying the next of kin of battlefield fatalities. Instead, the telegrams were given to taxi cab drivers for delivery, as depicted in the film We Were Soldiers. Unlike the film depiction, Moore did not actually assume responsibility for the delivery of the telegrams, however, she accompanied the cab drivers that delivered the telegrams and assisted in the death notifications, grieving with the widows and families of men killed in battle, and attended the funerals of those who fell under her husband’s command. Her complaints to the Pentagon, and the example that she set, prompted the Army to immediately set up notification teams consisting of a uniformed officer and a chaplain.”