The research was carried out by social scientists at the Universidad Católica de Valencia at the instigation of local chef Rafael Vidal. The researchers questioned 400 amateur chefs aged over 50 from 266 Valencian villages.
The results were published in the International Journal of Gastronomy and Science and were presented on Thursday at a meeting titled, A nightmare glocal discussion: what are the ingredients of paella valenciana ? (emphasis added)
I read a report somewhere (Petit Propos Culinaires?) about a bunch of Brit food professionals who went to a paella conference / presentation in Spain and the presenter at one point said to add a few sprigs of rosemary or a couple of dozen snails. Turned out they put the snails on rosemary bushes to clean out their digestive tracts before cooking them.
To clarify the article, seafood paellas are ubiquitous in Valencia. It’s just the specific dish called “paella valenciana” that does not have seafood.