Single Townies and Their Children Look Nothing Alike

This can be reproduced by creating an empty world (deleting all families in Other households) and visiting a park in Mt. Komorebi.

The park lot spawns children and teens. The game (mostly) doesn't spawn households with only a child in them and uses household templates to generate parents/siblings. 

Some of the household templates used for this don't use specific archetypes (they are not the summit-world specific templates). The resulting family will have a "requested" sim that conforms to the Asian archetype (a child or teen) and a randomly generated parent, sometimes a sibling.