I just read the new cookbook from Roberta's in Brooklyn, in which it states that they use Ischia starter and cake yeast at the restaurant. The book didn't go into any more details. I was surprised to see the use of the natural yeast.
I think you misread it. They say they use Ischia starter. They don't say anywhere that they use cake yeast. They do mention commercial yeast on that same page but don't say they use it. They then give two recipes for dough, one with starter, one with commercial yeast.
What I found interesting about their sourdough recipe is that they "tightly wrap" their dough balls in plastic, right after kneading and put in the fridge to proof. There's no rising time at any point in their process.
Both of these pages can be seen by going to Amazon and clicking on "Look Inside" for the cookbook. The dough recipe is on p. 32, the page about pizza dough is right before it (unmarked p.31).