In the example regarding the camera rig, is the camera constrained to the bone perhaps? Because I tried replicating the setup showed in the video, however I can't seem to make the camera bone point toward the aim bone when you move it's location. I actually used just three bones instead of a camera just FYI, so I'm not sure if that affects it.
But basically, the I set up a constraint in the MCH - Aim bone that copies the rotation of the camera bone, and for the actual aim bone, I set it's override transform to the MCH - Aim bone so it's basically taking the transformation of the MCH - Aim bone.
What's happening is that when I move the camera bone (just the location), the Aim and MCH - Aim bone doesn't move. Only when I rotate the camera bone would the two Owner(?) bones move.
But in the example you showed, it looks like even when u move the camera (just the location), it's being rotated as well, like it's constantly tracked to the aim bones.
Is there any other step I'm missing perhaps?