Yes, 2019.2 needs a bit of tweaking in order to be usable. I would not suggest upgrading the major version (2019.1.x to 2019.2.x) and there's a couple of reasons why.
1) There's been a lot of changes from 2019.1.11 to 2019.2.9, so the quiz/exam might ask you something you have no idea about or can't answer accurately because the feature looks different or simply has been reworked.
2) You may be able to fix the most obvious problems by looking in the console, but it's harder to find and fix those issues that do not appear as a script error - like a sound that is simply not getting played. That same sound might be something you need to listen for in an exercise. For the approved major version, we already tested each step-by-step exercise + much more.
That said, almost all of the teachings you'll get from Wwise-301 will be valid in today's use of the Wwise Unity Integration. The biggest differences will be in Wwise, and the changes in the Wwise Unity Integration is mainly things that make it easier for the user - like memory management.
Long story short, for Wwise-251 or Wwise-301, use the newest Wwise 2019.1 version.