The official line is that it apparently all just takes too much time. What else exactly is she doing that keeps her so busy? The school run? Doubtful. I'm thinking the more plausible explanation would be that Sir Phil finally realised nobody with a clue has wanted to dress like Kate Moss for about five years, and everybody else already does. All Saints does a better Moss homage than Moss herself.
The most interesting thing she has done for years is admit that to be really thin you have to not really eat.