My daughter, son-in-law and 6 year-old grandson fly into Orlando several times a year to visit us. They do not have status and are never assigned seats together. My daughter just gets on the plane and puts my grandson in the center seat where he has been assigned. She just smiles at the passengers on either side and explains that Delta could not seat her next to her son. Passengers are never excited about having a six-year-old child as a seat companion.
Our grandson has never flown without a parent next to him. Someone always elects to take daughter's middle seat rather than flying across the country with a six-year-child. On her flight last week she put grandson in center seat and said to the adjoining passengers that grandson was quite cranky and she was glad that Delta did not require her to sit next to him. Both passengers gave their seats to daughter and son-in-law.
I do agree, however, that Delta could do more to help families sit together. Occasionally a gate agent will do that for my daughter, but only about 50% of the time.