Nope, it changes a bunch of the rules, to a good amount. The Core Rulebook has all of the elements of the old Core Rulebook plus expanded campaign tools, Tartarus Sector, Solo Rules, and Life Paths. Besides the mechanical rule changes, the lore is the same. Oh, and visually, stylistically updated.
It does not include the old cinematics and campaign books. They are getting updated mechanic and look wise, but can be bought separately. They do say that if you had the previous PDF of the campaign books, that you'll get those for free when they're ready.