I don't see this issue reported, nor can I find it on github (maybe it is there and I just cannot find it). It is well known.
With the current patch, probably when observers are allowed, after you die, you cannot chat to anyone in-game anymore, only to observers (like here:https://youtu.be/cQ5lwfh8ejA?t=1249), but you can see the opponents side too. So if you have speech communication, you can cheat, as BH did here https://youtu.be/cQ5lwfh8ejA?t=2451.