his helps prevent shocking the exterior of the cheese and reducing the permeability of the rind to the brine
If it really mentions porosity, then IMHO that is not factually accurate, as porosity seems to decrease with higher temps (it's not intuitive, but that's what studies have found). There's more to permeability than porosity. Maybe Gianaclis is just using the wrong words to describe the phenomenon. Because the end result is as described, that the cheese will not have as much salt as when using cold brine and cold cheese.
If you took a really warm, cheese, say 90F, and put it into very cold brine, say 45F, what happens is that salt will still penetrate, the porosity is quite good. But the rate of that ionic movement is slower than with warm brine. As a result, the movement of whey into the brine is slower. So you get a salt gradient with more salt at the surface. This higher salt gradient draws more water to it, which makes for a softer outer layer. That does affect the salt uptake, but it has very little to do with porosity.
In contrast, say you cooled a cheese down so that it is more in line with normal brine temps of about 50-55F. It would have less of a gradient, and more salt, and as much or more moisture.
In practice, this isn't a big deal, as you can use brine concentration to more than make up for any issues.