The JWs I know think it's wonderful that the book is being studied again. Faith strengthening to see how everything fits together like a jigsaw and it's so obvious that the end is near. Even the changes are seen positively - it's a sign that the FDS is on the ball and keeping up with "current" truth.
Personally, I think it's being covered again because they've run out of books to study - it was cheaper than printing a completely new publication.
Maybe the GB members are getting tired or the inspiration isn't flowing like it used to. Can you imagine the effort involved in writing a new book and then making sure that every comment is in harmony with other recent interpretations.
penny2