Yes, but only because they lag behind Google in this regard. Companies embrace and propose open standards in the areas they don't dominate. As soon as you hit a core competitive advantage, they get as closed as possible.
It's not because they don't "dominate" in the area of building network hardware that they release their designs. It's because this is not what gives Facebook an advantage in the social products space.
There aren't better social networks out there that would thrive if only they had better network switches.
I'm not so sure of this. Google has published multiple documents [1] mentioning the limitation of top-of-rack switching capacity and data center bisection bandwidth: how they need to design around it, and why it makes sense to use commodity switches despite the burden on software design.
I didn't read it to see what you were referring to, but that's the second edition of an older book, so maybe they didn't update everything for the new edition. Google has been banging the software-defined networking drum for a while now (configuration is part of the compute engine APIs now, for instance[1]).
