First off, there will be some naming confusion, because the North American naming versus the European naming were different, with the word "rated" meaning opposite things.
In the European system, the "rated" number was the very unrealistic high one, based on the NEDC rating agency. And "typical" was the lower, more realistic one.
In North America, they had one called "ideal", which was the high one, and then "rated" was the lower one, based on EPA ratings, which is lower and more realistic.
So, to answer your question, the higher values were really not attainable, and so they just bothered people and no one used them. So for the newer cars, they are only using the more realistic lower value.
