Well, like the OP said, WI the Kaiser during the Savarejo Crisis(Franz Fernidand assassination) and the consequence put in work of the Schlieffen Plan, ask to the Netherlands an alliance in the war in change for Belgium Territories(Flanders and maybe wallonia too) and maybe some colonies in the victory(like co-dominum of the Congo or some similar).
What Impact will have in the first phase of France Invasion?(now the German will have more troops because the Netherland will help with the control ol belgium)
How will be now the Pacific Teather(because the Dutch East indias are a lot of inlands and that maybe can make some interesting butterflies with the japanesse)
Maybe will have a serious backlash in the newly born by Blood and Iron South Africa(because remember a lot of Afrikaneer are ethic Dutch and that will have a impact in their moral)
can help the CP in long turn or now Netherland will suffer a 'versallies-like'
well i excepct the comment, that was some interesting when i start of think about