As a gay muslim who had armed many ofthe rebels it is unlikeley but possible that Stevens knew that his “capture” by the daaaastardly rebels was part of the script. And that neat, intended chain of events was overtaken by the fog of the smokey battle that ended up playing out, with Stevens and the others all dying on that well-filmed stage.
There is planning but then there is messy reality also.
The academicians do not understand the sort of people that SEAL training turns those men into.
The whole made for tv script came apart because two SEALS were at Benghazi. No one had planned for that. The SEALS became the ambassador's security and rewrote the script thus saving America.
I do not believe Stevens was part of the plan. A good plan works when few people know what is going on. Also more realistic in negotiations that he doesn't know of the plan. When questioned afterward he will tell the truth according to what he knows and block any further digging into exactly what happened. He was no in the plan as a designer of said plan.