I am noticing this more frequently in recent episodes: Vocals are being distributed on the stereo channels depending on where a speaker is in relation to the camera.
This can add acoustic information and some pseudo-realism (if not overdone, which happens when factors like sound reflection on walls are disregarded), but it is a tricky thing to use, because it is very easy to break immersion with it, and this happens especially when a speaker's position changes not by moving, but due to a changing camera position. Because then the watcher becomes aware of a 'camera man' teleporting around in the scene.
I think this is especially noticeable in MLP because lately they're overdoing the stereo separation with lateral voices.
I don't know why people who get paid for this stuff ("professionals") don't notice those subtle but crucial details, but I guess treating this area as an art form might be more than what is the norm in the business.
This isn't a rant. It's just that I keep noticing various things that disturb immersion and would love to contribute my expertise, but unfortunately things aren't that easy.