This is probably the most useful type of voice call*. Just now I mis-threw a grenade and tried to warn a friendly by shooting at it since I had no headset on. If there was a "GRENADE!!!" voice call* he'd live. It would probably be the most used voice call* of all, especially now that AI uses them very competently.
If you have the sound file or can get a hold of those great voice actors, do it!
*By "voice call" I mean an intentional radial-menu action.