Maybe they have changed. Below is from a 6/21/19 email.
Thanks for that. Honestly we are not sure right now. We have not found one truck without the trail rail system locally and it appears the bed rails could be very difficult to work with. Might only be a tack option only. The good news is...
Can you add a trail rail system to the Sport model? I have been looking at the Diamond Back Covers and they are only making covers for beds with the trail rail system.
If I buy the sport can I add the rail system after the fact?
Thanks
Jon