The issue really isn’t whether or not the file was made for BD compatibility or not. Even if we didn’t care about that, it would still be rendered with the same aspect ratio (vlc would just add it like it does for 4:3 video). Even if there was more than just you requesting this, the logical thing to do is release the intact film. You can come along and do whatever you want to it. But if it was released the way you want, there would be no way for the thousands if people who want it intact to uncrop it. Does that make sense?
I think you are misunderstanding his original post. He never complained that the video wasn’t cropped for the preservation. He was stating that he wanted to crop it himself in VLC, but the letterbox didn’t allow him to easily accomplish that goal. He didn’t understand why the letterbox was needed, rather than making the video 1920x816, so that a straight crop can be done. So yes, it has everything to do with BD compatibility.