No, static variables aren't serialized. Like Stanley said, first z was 9, then the code incremented it, so now it's 10. If you remove all the code which serializes and deserializes objects from that example you will see the same thing happening.
Yes please, help us identify which topics that are in the guide written by Kathy Sierra and Bert Bates are not in the exam, since they mention almost all the topics are includee