I think his point is that although people are often interested in parallel behavior, they should really focus more on concurrent design to avoid/remove the dependencies that ultimately limit parallelism. Slide 19 mentions automatic parallelization, but his point is that developers should think more about concurrency and not that Go will automatically maximally parallelize concurrent programs.
Yes. For the underlying system to be able to detect and run in parallel you need the concurrency. Without concurrency your application will be run sequentially.
