That talking point is almost never used in reference to upper middle class Blacks, which is what this family in the trailer is. I wouldnt read any deeper into that tagline than what it is, just some surface level commentary about how man is his own worst enemy.
Upper middle class blacks are some of the prople who use that phrase. My guess this may be a family of c00ns or boujee folks who look down on poorer blacks. The howard sweat shirt and the beach house gave off they were “well to do”. And I remember reading that “Lupita has a past” in this film, so wouldnt be surprised if the other “family” are the incarnation of the black people folks say to “avoid”.
The husband seemed nonchalant when he went out, but noticed Lupita looked shook and told the girl “put on your shoes”. Hence she may know what this is from her “past”.
Lol thats just me going off of what has been presented though.