This is why they are so focused on the authority of the governing body, and why it is so difficult for them to let go of the 607BCE date and the 1914CE date. They use those to explain how Russell was guided by Jehovah into making an accurate prophecy that demonstrated that he (and they) were God's chosen. And if they are God's chosen, then whatever they say must be correct, and whatever anyone else says must be wrong.
They also need for JWs to only understand that superficial explanation, otherwise they might learn that Russell wasn't even close to getting his predictions right and that subsequent leaders edited his past to make it seem like he got things right. And, of course, lately they've had to admit that they're not all that special and that --in spite of being the only channel through which Jehovah guides humanity-- they get things wrong all the time.
But what hasn't changed is their policy-- disagree with them, and you're an apostate.