Nothing should be allowed to be called "Premium Economy"

Premium doesn't have to mean "elite," it might also refer to a risk premium or any situation where a buyer has to pay extra. ;)

Eh, they already had economy plus. Premium economy is basically traditional domestic business class on widebody international flights that have lie-flat business (Polaris) seating as well. Honestly, putting it in the economy bucket in contrast to Polaris seems pretty honest in the scheme of things.