Is it possible to implement a config command to the server config file that lets the Server Owner decide if Side/Global Channel Voice can be enabled or disabled.

Since Arma 2, you have to use third party mods to disable the Sidechannel Voice Chat.

Maybe add the commands:

sidechannel_voice: 0/1
sidechannel_chat: 0/1
globalchannel_voice: 0/1
globalchannel_chat: 0/1