I just call it a cheese to refer to it lol. I cant say it's a cheese due to fact that it's not exactly a special circumstance in which you have to do unintended things like pulling the ethernet cable from Crota or the bridges where you had to go above the kill area and outside the map. Or Atheon having the grenade fear and templar being pushed off as well with solar. Those are true cheeses because they took advantage of a glitch or the mechanics of the game to cheat. Riven on the other hand is more like a smart strategy. You dont need to pull a cord or back out or anything. All you need is high light and rockets and use the bluffs smart for melting point and well and in a way I can see why people think it's a cheese but it's really not because it's not breaking the actual laws within the encounter. Yes I know 3 people a room but unless the other 3 cant get to said room unless they find a way around the map and break the map kill barrier to get there to have 6 people then no it's not a cheese.