You don't need to rebuild the Wwise 2016 integration to use our plugin. Just drop the dll into the DSP folder in the Wwise Deployment location (for relevant 32/64 bit platform) of your Unity project.
Sorry for the confusion, we're working on updating our docs with this info.
I can confirm this though you guys should really explain this in your documentation. I just spent a ton of time trying to figure out how to do it the old way.