When a unit is far away from the squad leader, the squad leader will periodically order that unit to return to formation over radio.

Humans often don't use the ingame commands to order other humans, so the "Return to formation" radio message gets player even though neither the squad leader or the receiving unit actually wants that command. In missions with lots of human players in the same squad, these radio messages quickly become distracting, to the point where people will turn the Radio audio off in settings / get a mod so the sound does not play.

My suggestion is to not play the "return to formation" radio command when both the squad leader AND the unit being told to return are players, rather than AI.