They have always been a port installed accessory if selected at the time of ordering. Makes perfect sense not to have a rack of side steps holding up an entire production line when so few people order them. Port installation is outfitted for limited order options they do them on a daily basis and have the experience. They also handle bulk additions like floor mats, all weather mats, toss in the owners manuals etc.
The next step up from port installed options is having them installed at the dealer by a tech that most likely has never installed them before, takes several hours longer and billing reflects that.