I worked at AMD for five years and I can confirm this, with great and probably unnecessary detail.
AMD split into two companies about 15 years ago. The design side of the house which is still AMD, and the wafer fab sites which are now called "Global Foundries." They did this because the manufacturing side was sitting idle part of the time, at times when AMD didn't require as many wafer starts. Idle time in a wafer fab is basically just lighting billions of dollars on fire, so they decided to split off that part of the company, so they could act as a foundry for many other semisconductor design firms. Originally, AMD products were still supposed to get first priority, but I imagine now, the space goes to whomever pays the most for it.
Intel is the only major IC producer that has its own fabs.
Then there's companies like Samsung that produce some low-level semiconductors and memory using their own fabs, but they're not really doing complex ICs and microcontrollers.
I will take exception with some of what the dude is saying, if he's implying that there's no money to be made on manufacturing old chip designs. You can think of the semiconductor business as being analogous to the pharmaceutical industry. Huge initial investments in R&D, plus huge initial investments in setting up a new product manufacturing line in a wafer fab, result in profits being delayed heavily into the lifecycle of a product. A CPU company like AMD might produce a version of an IC for 2-3 years, and only actually make profit on it, for the last 6 months.
Consequently, the idea that producing "old technology" generates little money, is false. In fact it's quite profitable to harvest more money on old designs, once all the R&D and setup expense are covered.
Another problem with his assertion, although he never states it explicitly, is that he sort of genericizes the idea of "chips in cars" as if they're all the same and sort of homogenous, and they're all really old. In a modern car, there are 30-40 different ICs. Some are quite new and modern, and some are of ancient design. Some are simple, some are super-complex.
But it's still true that manufacturers eventually want to move on. There's SOME of that at play here, but it's not THE REASON.
We're seeing the same thing in glass for computer Displays. Smaller screen sizes just aren't all that profitable for manufacturers, and if you look at the market you're seeing everything under 24" slowly disappear. We're also competing with TVs, which have gone even larger. In a couple of years, you won't be able to buy a monitor under 24" in the USA. China/LATAM and emerging countries are another story of course.