Thats because CS at Berkeley is definitely not about what programming language/version you use. As a relatively recent graduate (december 2014), I can definitely say that the major teaches computer science, not programming with X, Y or Z language.

Ironically, I think this leads to knowing the languages that are incidentally used better than if you focused on the language itself (Python, Java, Scheme, C, Assembly predominantly)

Finally, not as much time is spent on that because it is much more valuable to students to see improvements in instructional material semester after semester, and changing from Python 2.X to 3.X really doesn't contribute much to learning the AI material