Sony cannot buy White Wolf. White Wolf is privately owned.
White Wolf will not ending Sony lots of money. If the case is without merit it will be dismissed long before in front of a judge.
Venturing a guess, White Wolf _must_ protect its intellectual property. I'm not saying that the case has merit, I don't know. But White Wolf must take a stand to do this. Because the next movie/book might be a little closer to the intellectual property that is White Wolf.