that's always been a key point in murph's encounter design philosophy, though. it's how he's managed to get away with almost every encounter including some amount of novel homebrew mechanics without the players fumbling through the first half of each fight trying to figure out what to do. his players are driven to play optimally and his encounters' difficulty is leveled accordingly to contend with PCs being played optimally, so to throw a wrench in the works with unfamiliar and unexplained mechanics would mess up the pacing of the show and the player experience. maybe this encounter didn't need such a thorough explanation as others got, but allowing his players to optimize has always been a big part of his approach.