It's literally something many companies do that ships physical products (especially electronics) and you're often forced to by your supply chain. Real life example:

I was consulting a company that designed and manufactured parking meters and those were powered by a little board running Windows CE 5. Unfortunately this board could not run Windows CE 6 (which did not exist at the time the product was designed) and at some point MS stopped supporting CE 5 so there were no more updates. This was pretty bad because (a) vulnerabilities weren't fixed anymore and (b) when the US changed the DST rules in 2007, all these things were tracking the wrong internal time for a couple of weeks per year.

So learning from that, the product manager decided that the lifecycle of a parking meter would now be limited by the rated OS of the main board's support cycle and 2 years before the end of a cycle a new model had to be ready for production. Most often "upgrade solutions" included upgrade kits where the customer would basically buy new guts for the device, but in the end, yes, this is planned obsolescence and it is standard practice.

Unfortunately, there's probably a bit of truth to your statement. I know that it's a talking point for the anti-capitalist crowd, although it doesn't necessarily make them incorrect. Their solutions however, tend to be pretty horrific.