That's reportedly how Alan Blumlein originally described the potential usefulness of stereo (which he actually called binaural recording and reproduction even though it was intended for speaker playback) to his wife back in the early 1930's. My paraphrasing- "When you go to the talkies (movies with sound), imagine the locations of the reproduced voices following the image of the actors as they move across the screen".
Perhaps ironically, once film sound did become stereo, this vocal following aspect he described didn't apply well to theatrical reproduction because it only worked for those sitting on or near the center-line of the theater. The practical real-world compromise for stereo film sound was driven by the practicalities of theater and auditorium reproduction - music and effects in stereo but almost all dialog reproduced from a central monophonic 'dialog' speaker, except for rare occasional off-screen dialog which is more in the realm of effects. In that way the voices stayed locked center-screen even for folks sitting way off to the sides. There were a handful of films made with stereo dialog early in the history of stereo film sound, but not many.
Interesting that the sound guy used the vocal panning technique for this ensemble. I'll listen for it on your binaural recording. It should work correctly there due to your center recording position, but of course there is no visual reference to compare with. I wonder how it translated for far off-center listening positions during the performance. Did you chance to walk around and notice what happened with that panning when standing off to one side? I can see it working for something less-literal and more-atmospheric such as this kind of musical performance - audience expectation is different for one thing. Also I imagine far off-center listeners might not experience the vocal panning as being closely linked with the singer's stage position in the same way as centered listeners, but as long as the overall vocal energy and clarity remain sufficient even with far-opposite-side panning positions, it might still translate well as a sense of closer/further and increase spatial interest, even if not spatially accurate position-wise.