Yes, Ontario (where the study was done), has such a program. An emissions test is required every 2 years on every car more than 7 years old.
The major loophole is that if your car fails, you only have to spend $450 to fix the problem. Spending $450 to improve emissions gives you a pass whether or not it actually fixed the problem or not.
Ontario uses a lot of salt in the winter, so there aren't a lot of old cars on the road.
The number of vehicles on the road that are older than 20 years is shockingly low, especially American brands which rust considerably faster than others. Even cars from 2000 are rare.
In places where there's no extended winter weather I've noticed the cars are often older, with 40+ year old junkers from the 1980s looking, by local standards, no more than ten years old.
The major loophole is that if your car fails, you only have to spend $450 to fix the problem. Spending $450 to improve emissions gives you a pass whether or not it actually fixed the problem or not.
Ontario uses a lot of salt in the winter, so there aren't a lot of old cars on the road.