It's interesting to me how Norwegian is one of the top 25 strangest languages in the world on that list, but Danish and Swedish isn't. Maybe it was on the lower end of the top 25.
One possible theory is that it could be related how the data set deals with (or fails to deal with) Book-Norwegian vs New-Norwegian. Also modern Swedish and Danish grammar only uses two genders while Norwegian still has three, so that could weight in.
Actually, Swedish and Danish ARE very weird, but they didn’t make the cut-off of “14 or more of the 21 features attested”. Swedish has 12 of the 21 features listed in WALS, Danish has 13. Both of them are actually weirder than Norwegian (15/21 features):
