No they will not.
If anything, the global center of Zorastrianism is now India. If there is a reversion of Iran (and indeed of other once Zoroastrian nations) to Zoroastrianism somewhere down the line, they will look to the commnity in India for their unbroken lineage and heritage roots. Because the fire has been burning un-interrupted in India, while contrary to the rumors of underground fires in the bowels of some mountains still surviving un-interrupted Iran today, what actually happened was that most of these fires (atash) were re-resurrected only a couple of centuries ago, after centuries of open persecution of the ancestral religion that was forced underground.
Parsis and Zoroastrian Iranis still visit Iran annually as a pilgrimage to their ancestral historical places, but the throbbing heart of the religion is now wholly Indian. The Parsis as a community may or may not die out eventually, but the religion they protected and nurtured for the 2.5 million practicing Zoroastrians still left the world over, never will. And that heritage is now India's. Not that of Islamic Iran, which at best is only the physical and geographical repository of a lost faith.