Often what obsoletes a product isn't the design or demand, but parts availability. A few unobtainium parts is all it takes to bring a production line to a screeching halt. In a perfect world everything would be made out of #8 machine screws, 2N2222's and .01 caps. But today's equipment has likely quite a few sole-source parts and not just IC's, but passives, connectors, power transistors, flex circuits, and even mechanical hardware. Things like processors or logic that go away are probably game over but even "simple" things that drive an assembly re-design nix the product because the updates and requalification cost more than the bean counters believe they will recoup. So when you've got a product that runs as long as the 7200, the TS-2000 or venerable IC-706 that tells me the company has some serious reach with it's vendors in terms of component sourcing, or as I learned in the case of Icom, they often warehouse a lot of parts and keep them a very long time. But even they will run out eventually and if they can't be gotten on the secondary/surplus market, then you're pretty much done. A company I worked for had a product that required a particular IC that went unobtainium and ultimately they ended up buying leftover bare die from the manufacturer, and having a different company die bond and package a few hundred IC's for us. Can only imagine what that cost but for the right product maybe worth it. Probably not for a <$1K ham radio.
Mark K5LXP
Albuquerque, NM