Time to bump this age-old thread!
The windows cvar "windows_speaker_config" no longer exists on CS:GO as of 10/3/2018, and the last appearance of MacOS that I've seen is 5/29/2016.
Edit: As of 4/9/19 I've obtained cvar lists from Windows, Linux, and Mac on CS:GO, and have updated detect_os.games.txt, which I've attached. Mac & Windows specific cvars broke some time ago, Linux has been fine.
Having some issues with Bitbucket's mercurial so when I get some free time I'll look into PR'ing the change to Dr McKay's repo. I'll also do my best to keep it up to date (for at least CS:GO) in case of future issues on my github: https://github.com/sneak-it/PlayerAn...t_os.games.txt