Light trucks aren’t exempt, but have a different standard. The article posted lacks a lot of detail. First off, 50 mpg is just the expected average given the mix of “light trucks” and cars. The actual standards are 65 mpg for cars and 45 mpg for “light trucks.”

The new standards require American automakers to increase fuel economy so that, across their product lines, their passenger cars would average 65 miles per gallon by 2031, up from 48.7 miles today. The average mileage for light trucks, including pickup trucks and sport utility vehicles, would have to reach 45 miles per gallon, up from 35.1 miles per gallon.

https://www.nytimes.com/2024/06/07/climate/biden-mileage-electric-vehicles.html

So actually the light truck standard isn’t far off of the 50 mpg figure this article inexplicably comes up with even though that’s not the standard for either cars or light trucks under the new rules.

Heavy trucks and vans also are included in the policy with a greater percent increase than for cars and light trucks (though beginning from a lower floor).