You might click on either the tree pic or the words link on my first 2 posts. Both go to some overview info on ZA. It is a very old and complex belief system. Not very well known in the west.
I would imagine that if the mullahs would be run off, there would be interest in Zoroasterianism by some --- and some would study and return to that, some would look into Bahai, some would become Christian --- some Orthodox, some Catholic, some Evangelical, and many would be agnostic like it seems many already are. Freedom of religion would be a very good thing and liven everything up.