They're not just doing it to screw us. Based on what I'm seeing I'm convinced there are real shortages of specific components that are holding up some trucks. And with the changes to the packages and availability of certain options, they have been able to steer people toward lesser optioned trucks. From what I see, they're starting to build trucks with those options now. But it's not all that fast. And they have a long backlog to build through.
To summarize, I think they're building the most profitable trucks they can given the parts they have available.
There's a lot more to it than trim, cab, engine, paint color.