I’ve worked on Medical devices that had 20+ year product cycles, the EOL that was most common was NOR Flash from Spansion. They were always doing process node shrinks to cut their costs but each shrink changed the timing (usually making it faster). We needed to re-qualify it every time.
Now I’m doing consumer and there is a part shortage so there is also the need to qualify alternative parts to keep the production line fed with millions of components. I’ve tested what seems like 20 different derivatives of a photodiode circuit for the same function.
TI is notoriously good about EOL, other vendors can have other reputations.
Microchip is one who revs their chips more often post release. Some of their parts are on like rev E. It seems like they are more fast and loose on their pre launch verification.
These days I guess there are not that many tier1 silicon vendors to choose from.
Like @quozl suggested, parts in the PC and mobile supply chain are far more susceptible to EOL and shortages, sometimes they are made for a single customer and produced to order one fab boat at a time instead of forecast+inventory. When the single customer goes away or next gen silicon is out, there is no reason to keep the old part around.