Docker provides /dev/mqueue to containers because some applications require or take advantage of this features. Docker does not use this directly. You will see some people with the question like "why does my application run slower when inside a container than on my host?" There can be a number of reasons why but one thing with applications like apache2, it uses mqueue to help speed things up if available.
All the major distros have this enabled by default in their kernel configs and we have not heard of any downsides where you would require this to be disabled. If you know of a reason why then let us know.
Hope this helps and sorry for the gist, i wanted to explain in more than 140 chars.
6 years later, I am happy to find your gist (via duckduckgo).
As I fine tune my kernel I wanted to have a good reason to keep or not POSIX mqueue support.
I knew that was an application based requirement and thanks to your comment here, I just got the right hint, thanks :)