What this means is: I better refrain from writing a new book and we rather focus on more and better docs.
I'm glad. I didn't like that the book (which is essentially a form of documentation/tutorial) was proprietary.
I think it's better to make documentation and tutorials be community-driven free content
While Trailblazer offers you abstraction layers for all aspects of Ruby On Rails, it does not missionize you. Wherever you want, you may fall back to the "Rails Way" with fat models, monolithic controllers, global helpers, etc. This is not a bad thing, but allows you to step-wise introduce Trailblazer's encapsulation in your app without having to rewrite it.
At Google, we believe that if we focus on the user, all else will follow.