That notice reflects EPA propaganda for energy savings and to keep in step with washers that only offer cold rinse temperatures. The instructions on the box of powder say the detergent will not dissolve well in very cold water, yet say that cold water will rinse it out. Cold water temperatures range from above 90 in some places during the summer to 40 or below in other places durning the winter. In the wash, you are trying to get the detergent to go into solution. In the rinse, you are trying to get the concentrated detergent/soil solution in the fabrics to move into the clear water. Water that is below 60-70F will impede either process, even with liquid detergents.
I don't think American consumers frown on warm or tempered cold rinsing. In fact, some WP toploaders offer a cool rinse setting. Of course, it replaces the warm rinse temperature setting, but it's not stone cold. I doubt it matters to 95% or more of the people doing laundry. They select warm or cold wash for their gray and dark loads, fill the softener dispenser if available, and walk away. The softener masks any harshness from detergent not rinsed out of the fabrics.