Duplication might mean that you are repeating the same content over and over on your channel.
Some people lost their channel because they had visual content that was used or very similar to their other videos and only the music was changed.
YouTube doesn't want the system to be flooded with repetitive content especially when it comes to the kids category.
That statement makes me frightened for my main channel!
I do "video series" where Binaural Beat, hypnotherapy and self-composed Ambient Music are grouped under "themes". I tend to use the same video backing for each video in a series at times. I am also under a Music Aggregator who does "Album Art Videos" all of which will have the same album cover as video for tracks belonging to the same album.
That agregator is Phonofile which is a wholly owned subsidiary of Sony Music. If YouTube starts hitting music aggregators claiming "Duplication", they stand to lose some of their most lucrative commercial partners.
Looks to me as though there is another algorithm which badly needs tweaking if YouTube isn't going to be forced down the road to admit it has shot itself in the foot yet again.
