That article is talking about the quality of gas and not regular vs premium. Quality is very important and "top tier" is a rating that sets a minimum quantity of detergents and max water content. So it's good to try and find that top tier sticker on the pump but it's still marketing. Top tier is a company AFAIK that sells the label after verifying the gas meets their requirements. All gas comes from the same place in your area so the top tier thing is even more questionable.
Also that article mentioned regular vs premium and says not to bother using premium if your vehicle doesn't require it.