Your issue is one that Adobe is aware of (I think they cover it in this blog post: known issues in After Effects CC 2015 | After Effects region of interest).
I've heard from Tim K here on the forums that the AE team is developing a new way of delivering AE's preview to the screen and sound and this new way should fix a lot of this kind of bug. Hopefully it will come in the next update. In the meantime, filing a bug report will help: Feature Request/Bug Report Form
I looked on the page you referred to, but it states:
When you start a preview in After Effects CC 2015 (13.5), audio may not play for one or more seconds at the beginning of the preview.
This issue is fixed in the After Effects CC 2015 (13.5.1) bug-fix update.
which is clearly not the case, at least in my experience. I filed a bug report as you suggested and what you've heard sounds promising, but it puzzles me how this bug could still be occurring when it seems so fundamental. Thanks for the feedback.
Sorry, I thought they mentioned it there. I know it's mentioned somewhere! They said one bug was fixed, but a different bug (with similar symptoms) is still on the loose and they are trying to track it down and squash it..