How Convenient

I don't watch This Is Us regularly, though I'll sometimes check it out if I notice it's on.  I watched it last week and was surprised to see their latest plot twist.

Jack Pearson--everyone's favorite father--enlisted to serve in Vietnam as a young man to help out his brother, who'd been drafted.  Jack never talked about his war years to his family, but now his grown kids have discovered their uncle, whom they were told died in Vietnam, actually survived.  In the latest episode they go visit him.

Why is this surprising?  Not because the brother survived--everything about the Vietnam plot is tired, not surprising.  The surprise is this is exactly the plot twist that was used in the first season.  The adopted son, Randall, discovers his birth father, and it turns out his mom knew about the guy for years but never let on.  Now it turns out Jack was keeping his brother's life secret.

Just what sort of family are the Pearsons, where the parents keep the existence of major relatives secret?  If the show continues (and it's a hit so it probably will), will they keep pulling out new characters who were always around but not widely known when the producers are stuck for a new idea?