Unless they've moved backwards, that hasn't been doable for a very long time. The client in the past didn't have the information sent to it about things in fog of war. The closest was seeing a skill shot come across your screen and cheats gave an approximate location of where it was launched in fog of war.

Generally 3rd person shooters like CSGO and Valorant have this same issue, so its probably more complex than you think. Also, another kind of cheat is to display expanding areas on where an enemy could possibly be based on the last seen position.