We've known semblances can be hereditary to a degree since World of Remnant. They mentioned how semblances can often be similar to one's parents. 

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This episode simply confirmed that the Schnee's are one of the rare few to have a semblance that is completely hereditary. Hence actually passing down the whole thing not just a similar version. 
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Also [@Prince of Seraphs], I think KNVS is ready for you to begin antagonizing the mission. The airship is en route.