Is the new codex useless already!?

Hi all, sorry if I’ve gotten all this wrong but thinking of getting back into 40K and what better way to dive into the Death Korps of Krieg box. Always loved the lore and the models look good and finally in plastic. Now I might have heard this wrong but the limited edition new codex that comes with the book….. that isn’t technically even released yet, is it true that GW have made changes to rules and points which makes the codex out of date already!?