Observed in 0.77.109860. Doesn't happen when the radio isn't equipped, it seems the game just applies the filter to any kind of squad message independently of the channel being used as long as you have a radio.
Additionally, misc chatter causes orders to queue up. A squad leader shouldn't have to wait for someone to stop reporting that he's moving forward to give out an order such as telling the squad to move to cover when an enemy APC comes nearby (which the AI isn't capable of doing by itself). Talking over the radio should automatically cut off any kind of non-important message.