The same thing happened to one of my videos two months ago.
YouTube deleted the video without any warning and only with the same general statement.
They even warned me, that if I violate their guidelines again, they will delete my whole account; but I don't even know what kind guidelines I supposed to have violated!
The video was online again after two hours without any excuse and without any explanation.
Every time I upload a video, I have that fear that it gets deleted again