Hi Todd,
Family styles have long been taught to learners outside the immediate clan. This doesn't change the fact that it's still a family style. Look at the Japanese style of Tenshin Shoden Katori Shinto Ryu.
TSKSR is considered the personal fighting style of the Iizasa family and dates back to the mid-15th century. It has been handed down through the Iizasa family for twenty generations and taught to many learners who were not part of his family. These days, the family style is protected by Iizasa Yasusada, the 20th-generation head master of his family style, but he himself is not even a martial artist. Although this is a sensitive topic amidst the followers of the two different streams of this family style, it is, nonetheless, practiced by thousands all over the world and still considered "a family style."
Does this help?