One can write a book about literally anything. But besides that, it already "required" a book – at least two of them in fact, both published before Google even announced SPDY: "High Performance Web Sites" [1] in 2007 and its sequel "Even Faster Web Sites" [2] in 2009, both by Steve Souders.
What are they about? Essentially, optimizing your HTTP responses for the ways in which actual web browsers make HTTP requests. Any web performance analysis tool worth using (like YSlow and PageSpeed – both of which Steve Souders was involved in btw) recommended the practices outlined in those books.
So, no. I don't think a new book with updated practices says anything about the protocol. The optimization tips from this book will simply become widespread common knowledge the same way they did in the past.
[1] http://shop.oreilly.com/product/9780596529307.do
[2] http://shop.oreilly.com/product/9780596522315.do