That's actually a really good question
@Spitfisher.
It's just another list in a long line of having safety equipment mandated by the US Government for all new passenger vehicles to be sold in the US. Some people see this as being progress and the government looking out for us with sound science and compassion ... other's see it as being a nanny state where big brother is watching us and will tell us what is best for us, even if we disagree.
Anyhow,
Tire Pressure Management System (TMPS) has been mandated since 2008 and the law was passed in the year 2000 after the Ford Explorer problem (which was almost always due to people driving too many miles or going too many years on otherwise fantastic tires).
The only requirement is to have a pressure sensor in each tire that will cause the check engine light CEL to come on and/or a special tire symbol. Most vehicle now have some type of driver information display, so it will actually tell you your current tire pressure reading and/or will warn you when driving if you have a sudden drop in pressure.
Back when I was an executive marketing VP for a major car dealership in Dallas, I got demo vehicle all the time and I took out a large SUV that picked up a nail or something going down the freeway. Turns out it was a large puncture, but I didn't notice anything until the TIRE PRESSURE WARNING message turned on. I was able to get off the freeway, pulled over to the shoulder, noticed that it was hissing but the tire pressure started at 40, dropped to 30 and I drove to a discount tire shop, pulling in when it got to about 25 or so.
Discount tire pulled out the foreign object, patched the tire, inflated it and I was back on the road (no cost to me) in maybe an hour or so.