Some things have changed from 2.79 to 2.80
I changed the collection 2d_baker_panel_UI.001 to be un-selectable, (the cursor icon in the outliner)
I also had to load my audio into the sequencer, and then load my scene into the sequencer on top of it to get both to output.
And I had to use Cycles to render.
Hope this helps!
It worked fine while I was working, but it was tricky to get the audio and animation to output together. Maybe just something weird in my preferences, or a MacOS bug.
I had a black rectangle appearing around some mouth shapes in Eevee, but I may have just missed your update.
Hi-
I think this is the black box with evee issue, I downloaded the file 1/5/20 (US). When you look a he mouth materials, some of the settings are opaque, if you change them to one of the alphas they work.
I have a mac and the sound worked, in the video it shows you setting both the AV-sync and Frame Dropping, but in 2.8 it looks to me that you have to pick one or the other. I picked av-sync after reading about them. I could be totally wrong with both ideas, but thought it was worth a stab at an answer.