I no longer assume rationality on the part of businesses and consider doing so a serious mistake. Businesses often have short term thinking and have shown themselves perfectly willing to shoot themselves in the foot.

The original comment that started this thread listed a bunch of plausible and probable causes of branding changes, and all of them are only rational from the point of view of an individual and orthogonal at best to the improvement of the business they are working for.

It’s also possibly done because people train themselves to like familiar tastes. There might be a small drop in sales, but eventually as more customers buy the product they will get used to the new flavour.