It's not unreasonable. The gameboard the US has right now is not great. It cannot accomplish its goals with raw force, there isn't enough force to go around and it would cause too much foreign and domestic resistance to try and do so. So color revolutions, intelligence stuff, coups, assassinations, are all very much on the board and in play as the tools the US has left.

One need look no further than Georgia (the country) and the protests there. There is unfortunately a decent chance that the sitting president with the NATO trained armed forces there may pull a coup against the legislature if they try and pass that law, probably under the pretext of protecting the people, the usual color revolution narrative.

One shouldn't get too bogged down in the nitty-gritty, it's alright to assume conspiracies, entertain them when they make sense like this, recall back to past plays by the US in a similar vein last century but fixating too much on unknowns like this which unlike a color revolution really has an air of nobody but maybe the Iranians truly knows.