I remember someone posting the trucks used to determine the EPA rating. Some other configurations besides a V-6 Tradesman but I'm sure they were bare-bones with no options.
I don't think it's as much for us as it is for their CAFE rating. FCA (Stellantis) has to make
some fuel efficient vehicles if they want to keep putting the 392ci V-8 in more vehicles.
I know that FCA and GM buy greenhouse credits from Tesla already to avoid going "over" standards and paying heavy fines (which we ultimately pay for in the purchase cost). I don't know how many more rocks are left to turn over to find credits to buy other than use the bare minimum to establish EPA MPG numbers to get the most bang for their buck.
Realistically I'm sure that most other auto manufacturers do that too. I didn't expect to meet those numbers on the window sticker but it's a pretty good hit for anyone that did.