The book does discuss modules, in Item 15. I'm not all that enthusiastic about them. Here's the key paragraph:
Not only is the access protection afforded by modules of limited utility to the typical Java programmer, and largely advisory in nature; in order to take advantage of it, you must group your packages into modules, make all of their dependencies explicit in module declarations, rearrange your source tree, and take special actions to accommodate any access to non-modularized packages from within your modules [Reinhold, 3]. It is too early to say whether modules will achieve widespread use outside of the JDK itself. In the meantime, it seems best to avoid them unless you have a compelling need.
Time may prove me wrong, but I don't expect modules to have much impact on the platform.