They've had the Rh- blood and engineering topics on for years. In particular with the engineering topics... If anyone says that we currently know what our true history is, they're just flat-out wrong. AA does, IMO, a great job in delving into this topic with structures all around the world that could not have been constructed with the primitive tools alleged to be available at that time and in the "prevailing narrative".

I haven't watched that series in a couple years and don't recall many episodes on sound frequencies (with the exception of an episode in a cave system of some sort) so I can't speak to those kinds of changes in their content.