Straight in front is likely to be unobstructed while straight behind is likely to be obstructed by computer hardware. Therefore, straight in front is likely to have crisp sound while straight behind is likely to be muffled and/or distorted by reflections.
Yes, but that's not something you can beamform away with a planar array. Especially if your goal is to record what's going on behind the screen. You need something out of plane. Which they may have had! I don't know the details of the hardware.