Yeah, you are spot on, what you described is exactly what has been happening. There has been an explosion of both recordings being taken and ai being used to analyze them. I just would have kind of thought that with zoos or other elephants that were closely monitored someone may have noticed that they were doing this awhile ago. Ya know what though, elephants make noises that are outside of the human hearing range and the ability to analyze these sounds is also new, so that is probably another reason that this is just now being uncovered.