People seem to be operating under the illusion that Prussian militarism started and ended with Hitler. Granted he was the driving force behind pushing the war and pushing the generals to prepare to attack numerous countries, but doing so was already an ingrained part of the Prussian national psyche before Germany came to be.
The successful German Sickle cut through the Ardenne was not a result of Hitlers genius, no matter how much he tried to convince himself it was, but a combination of good planning by the German General staff, and excellent tactics using fast, powerful Panzer formations.
The reality is, once Poland is invaded, the Angol-French aren't going to accept anything less than full withdrawal from Poland, and probably Czechoslovakia too, which isn't happening. Therefore the war continues, and the Germans are still going to recognise that the longer it goes on for the stronger Britain and France get, and the weaker Germany gets. Ergo eventually they're still going to plan to attack France, and they're still going to recognise the need to bypass the Maginot line and hit the Ardenne.
What gets butterflied away is Barbarrossa in June 41, and probably the final solution too.