I think it is likely a (perverse) indication that the NYT is more successfully adapting and competing in the news market. But headlines have always been written with the primary intention of grabbing attention, modern web clickbait style headlines might be another evolution of that approach.

I've thought that Times article headlines have been more clickbaity over time. Some articles, especially if they aren't related to current events, are becoming more casual in their voice as well.

If they can maintain quality journalism by only sacrificing headline quality, that is probably a good and necessary tradeoff to make.