The title is quite misleading or doesn't give the full picture of their conclusions. Indeed, this is at the individual level, the collective will likely suffer from the use of AI...
Anil Doshi, Assistant Professor at the UCL School of Management added, "While these results point to an increase in individual creativity, there is risk of losing collective novelty. If the publishing industry were to embrace more generative AI-inspired stories, our findings suggest that the stories would become less unique in aggregate and more similar to each other."
Professor Hauser cautioned, "This downward spiral shows parallels to an emerging social dilemma: if individual writers find out that their generative AI-inspired writing is evaluated as more creative, they have an incentive to use generative AI more in the future, but by doing so the collective novelty of stories may be reduced further.
Although, I'm not sure this is as dramatic as it sounds... thinking of it as an illustration of regression to the mean. Non-creative writers will benefit from this, bringing them closer to the base level of average creativity. But exceptional writers won't, they have no reason to become average. So they have no reason to use AI to standardize their writing. We'll end up with crap being less crappy, but good content will still require someone's unique creative juices to do something exceptional.