It is current. Discusses structured streaming as well as datasets/dataframes in spark SQL. RDD's surprisingly are discussed after streaming and SQL. This makes sense I guess, given that in the industry, developers are working user higher level structures like dataframes etc and not low level structures like RDD's.
The book is really awesome, have complete only half of it and can say that it is the most informative book on Spark. The code examples work out of the box in databrixks community edition, but in a standalone node you have to do some config. Would be great if the author includes the config files like hive-site.xml etc in the github repo