Scientologists don't try to re-write history the way Dubz do, they just don't release the info until a supplicant reaches a certain level. Their core beliefs are the same ones that L Ron Hubbard penned for his SF series over 40 years ago.
JWs are just absurd. In their quest to vomit forth all those books and rags to sell, they frequently release info that contradicts with info already released. It's just the nature of the beast; write enough words and sooner or later something will slip out that doesn't jibe. Jehovah would probably catch the errors for then but he has left the building!
It's really their own fault don't you know. In an effort to control every aspect of the Dub's life, from how much to eat at breakfast (every Assembly KM) to how many people to invite to your wedding reception (10/15/2006 WT), the Org has made sooooooooo many rules that each new one tends to contradict a prior one at least in some way. Don't even start on how many blood changes there have been in 40 years. I think it's over 40?
That's why you are not supposed to read old ("old" being ten years) literature. Even the most jaded Dub might raise an eyebrow when they realize that the Organization they were part of changed somewhere along the way. To call their core beliefs "fluid" is really an understatement (which is the same as saying they HAVE no core beliefs)