I was surprised that my KL flights over the last two weeks posted in two days along with the NW leg (DTW-AMS-NUE and back). The return was even a rebook to get home a day, plus a seat assignment chance when they went from a F70 to F50.
Could booking the NW codeshare number instead of the KL number matter? I made sure it was a NW number since this can affect some promotions.