The definition of redesign, per the Merriam-Webster dictionary, is to revise in appearance, function or content. In packaging, that happens more frequently than one might imagine.
When brands are considering a new design, one question to answer is: Why? Is it for a more modern look, such as digital printing or other special graphics effects? Is it to revise the text placement? Change colors for an entire product line? Change to sustainable materials or another pack container?