@Skar,
I don't think it's so much the time of writing that is important, Skar. Unquestionably, the term is used, still, to mean ancestor. I see it pretty much as you do. I don't think that dictionaries are much help here for the simple reason that they state it is 'archaic'.
This has led me to rethink what they mean by such a term - 'archaic' - are they not misusing that word???? While I'm certainly no spring chicken, I think that archaic is a tad premature.
It has also led me to rethink some of my previous positions on words, although right now I can't recall which words they were. Does that indicate the I am, indeed, archaic?
Perhaps corpus studies might show that they could have more accurately used the term 'dated'.
Are 'groovy' and 'far out, man' archaic?