They probably/usually do but I am not sure if this is the major reason behind the change in hod way I perceive the taste. I suspect the changes in myself may play a more definitive role in this.

> Dont they usually change the recipes?

Sometimes. Sometimes it also might be a process change.

There is a desert people in Hungary quite like. It's basically a bar of cottage cheese coated in chocolate. [1]

One day the factory manufacturing it received a huge amount of inquires about a recipe change. The only problem was that they haven't changed anything. As far as they could tell everything was the same as it always used to be. But still there were a lot of very vocal costumers demanding the old taste so they went and investigated.

According to the story what happened is that the logistic provider improved the refrigeration in the supply chain. Because of the cottage cheese these deserts require refrigeration. Of course they were already using refrigerated trucks, but there was some transshipment centre where the refrigeration was missing or not very effective. And what changed is that they fixed that.

So basically the old taste, the one people demanded back, was the result of the cottage cheese just a tad bit bit ripe from the heat during transport.

1: https://en.wikipedia.org/wiki/T%C3%BAr%C3%B3_Rudi

Some companies spend an inordinate amount of money and time to preserve the taste (Budweiser apparently has tasters who travel the various plants making sure it all tastes the same, like water should), but many other things have had significant drifts over time (and it's hard to compare as you need actual double/triple blind tests to even begin to get accurate data).