Resolved upon release. In the event the book's name is changed, the next novel-length sequel in either series will win. (For example, if Rothfuss releases a surprise KC prequel that is not functionally the third book in his projected trilogy, that would not resolve YES--but if he just renames the third book "I hate writing here's the book give me my money and go away," that would resolve YES.)
If neither happens and the authors die or something, does this stay open until the heat death of the universe, or something else?
@Bayesian Yes. This will the tombstone of our culture in that event, the sole artifact of our entire history as a species.
@Hyperlincoln The question does not exclude the option of the IP being sold off and another author finishing the series. Given the hype for these, there is a decent chance someone will try to do that if the original author dies. (If it wasn't so long term, I would make a market on it.)
@UnconditionalProbability I think that's pretty likely, especially for GRRM. Doesn't affect this market, though, doesn't matter who the author is as long as it's the next book in the series.