Absolutely. If packaging and marketing stopped mattering so much once the public already knows a product well, Coca-cola could have stopped spending so much on their brand a long time ago.
If packaging and marketing stopped mattering so much Coca-cola would go out of business immediately. Sugar water is cheap and simple to make. The off-brands taste just as good if not better in blind testing. The only defense they have is their brand and the amount of money they spend on marketing. Same with Red Bull.