Sources differ on all that
I'm not sure we will ever get the whole story.
I won't start a debate over whether the revolution was justified or supported by the people or anything. That's not what we are here for, and I guess we're off-topic enough as it is...
I agree that there are chances the Afghan history wouldn't have changed that much though. Now the whole idea of the whole off-topic debate is what the Iranian OOB would have looked like, had the revolution not happened. Not sure that "revolution happens the next year" is the most constructive answer.
Not that I mean it couldn't have happened, of course.
I mean no offense here, but bear in mind that if we start discussing the hows and whys of the revolution, we'll end up in a few weeks and ten pages waaaay besides the original point of adding the pre-revolution Persian flag to the game.
Regards,
Plasma