Having tested this again, I wanted to follow up that I can’t replicate an issue with adding the Framework folder itself as shown in the tutorial so I don’t think this issue is precisely that it is necessary to import that folder’s contents individually.
It’s likely that re-importing the acoustic model files individually fixes something minor that has gone wrong a bit earlier in the process with the addition of that folder (for instance if the target was accidentally unchecked while adding or it was added as a reference and the reference was somehow problematic or became so later) so I strongly endorse gregquinn’s method described above as a troubleshooting step if you see a crash when listening starts.