This is the answer I got from a sales rep when questioning the payload info. Sounds like a bunch of crap to me but maybe someone else can make sense of it.
"In the 2024 Expedition non-max 4x4, Ford standardized the platform across trims so that the base curb weight, & thus the payload capacity is nearly identical regardless of interior or luxury features. Essentially, all trims use the same structural components and equipment, so the payload is determined solely by the vehicle’s overall design. The only exception is when the Heavy-Duty Tow Package is added, which changes the payload from 1358 to 1405 lbs. In previous model years, differences in standard equipment led to more variation in payload numbers, but for 2024 Ford streamlined production and ensured consistency across trims."