I'd bet that Luigi is just doing it the way he learned to do it. I don't think abusing the yeast by re-hydrating it in cold water is the correct way to slow down fermentation, but to each his own. I'm in your court, in that if I want to slow down the fermentation I'll just save a few pennies and use less yeast, or adjust the temperature of the dough water to give me a slightly cooler dough off of the mixer, hence a slower fermenting dough, but that is using a technology that everyone is not familiar with, which, underscores one of my main objectives, to provide useful information and increase the technical understanding of the ingredients and processes that go into the making of our favorite food PIZZA.
Back when I first started at the PMQ web site I was accused of speaking and writing in a foreign language. That was the language of "bakers percent". Today they all speak that language over there, and many of the long time regulars have developed an excellent understanding of the more technical aspects of dough, sauce, and pizza production.
Tom Lehmann/The Dough Doctor