I think there may be less familiar, remade content in the game than many realize and much more that is new, given how expanded Midgar has become. I don't think the sequence of events is going to be the same as the original, there's likely to be a lot interspersed in between it all, especially prior to the plate collapse to push it back until late in the game. And keep in mind that story changes have been confirmed, and I doubt that the watchmen are the only such change. So there's still plenty of room for spoilers, I think.
And it's quite possible that SE, in some ways, may take advantage of people's familiarity and knowledge of the original to flip certain things around and surprise us with the unexpected in order to keep us on our toes and get us to realize that we may not know as much as we think we do and that any knowledge of the original may only take us so far. That familiarity with the original lends itself to the expectation of things happening in a certain way, but SE may shift some things in order to deliberately play upon those expectations and throw them off, knowing that they are there and able to be exploited in such a manner.
