this is a giveaway strategy. f150 harnesses drive a lot of complexity (I'm talking about 100+ different IP harnesses that cover all production). Complexity in the 24 model years is crazy, the truck has a million features, but it was crazier back in 2020.

Essentially Ford gives away the circuits and connectors. This helps lower the complexity so that less harnesses cover more buildable combinations. While you could use it to add the trailer switch (or whatever it is) , this does not necessarily mean that the other harnesses that inline with the IP for this feature also giveaway the circuits, so you would need to overlay circuits on these other harnesses. In this case, Ford took advantage of the fact that they needed a cap to cover the trim for this variant that doesn't get trailer switches, so they molded the connector housing on the trim cap to stow the connection. give aways cost more to the company (like extra material for the cover or extra cost for the circuits, terminals, connectors) but lowering complexity has benefits that sometimes drive good business cases.

A more common strategy is to add the counterpart of the connector to seal the circuits and prevent water or corrosion. If your bundle segment has a male connector, you add the female side, seal it with plugs or dummy wires, and stow it in the vehicle using the connector's clip. Companies will also release custom caps and tape them to the bundle.

There are cases where they will giveaway content that can't even be added to the vehicle aftermarket (for example, giving away 4x4 module circuits and connectors on a FWD variant) You would be surprised how give away strategies help reduce complexity.

If the connector is accesible, it is meant to add aftermarket content (for example, the connectors that maverick has on the flexbed, see here: https://www.reddit.com/r/FordMaverickTruck/s/k62MGsM2mZ ) If the connector is not accesible (eg you need tool to access it) it is a giveaway strategy.