No, not all living ancestors of the family of musicians from 1504 are known. Even more: there are persons, which belong into this family, but they even really don't know this fact.
How do we know? We found several people and we mailed this fact to them.
How come? With our research of the Bach Genealogy we discovered much, which was not discovered even by the most experienced Bach Genealogists before. It's not the case, that we are "better" researching or doing science. The opposite is the case: earlier generations of researchers and genealogists had to seek even harder. The names Brueck, Frickel, Kock, Professor Krafft and Odrich are well-known to insiders. But all of them haven't had the nowadays options of the internet. This is what my wife and I have today.
We already do know, that we can include many more Bachs into the Bach Family of Musicians Tree. That is not only additional branches but more and younger members of the US Bachs, which have been born since the last genealogy publications. Plus there is exciting evidence regarding Veit Bach. But this will take more time. First things first, which is the accomplishment of this website.
99 Music Calendars, Composers Calendars and Bach Calendars