Some brands are just part of the everyday fabric of our lives as consumers. I doubt if anybody noticed when irn bru changed the design of their cans last year. They have tweeked it ever so slightly. The previous design had been like that for almost ten years.
fanta have also recently changed to a more youthful look.
One more obvious one is cadbury's hot chocolate . They change their packaging about once every three years. It has evolved ever so slightly in such small amounts that, again, hardly anyone notices.
We already identify with brands so much that if a designer was to radically re-launch a product that looked completely different, it would need a substantial amount of advertising to back that change up.
The small local brand oxenrig eggs changed their free range eggs packaging a few years ago. They have since gone from a small local brand to a regional, not quite national brand. Their boxes can be bought from