How so? All we know about first contact with the Klingons is happened centuries before TNG and it didn't go well. We dont even know which first contact it was. Klingon and Humans? Klingon and Vulcans? Klingons and Andorians? Its a bit a vague. The Human and Klingon FC meets the criteria since it happens roughly two centuries prior to TNG and as a result relations between Humans and Klingons got off to a rocky start that pretty much went downhill from there. So no change in what was shown in Enterprise and what was mentioned in TNG.