Is Retro back in fashion?

This WSJ video and article (behind paywall) is about examples of companies going back to the “good old days” when men were men and packaging was packaging.

I think it is interesting to look at it the other way around and question what was it that made the brands change the packaging in the first place. What aspect of design was it that caused the fonts, colours and images to change?

Is the purpose retro to re-ignite memories in the heads of oldies about the packaging of their youth? To appeal to a slightly younger audience who can only have the faintest memories about the original packaging? Or is it to appeal to the young who wouldn't have any memories but might dream about days when the believe world was good and they would have had money to spend? I am not really sure. Dick Stroud