Can X become dhimmis?

How can we know whether the followers of a certain religion can become Dhimmis? For example: In the hypothetical case that any neo-Pagan movement ever becomes large enough in a Muslim country or that a country that already has a large neo-Pagan community (like in Europe) ever becomes Muslim majority could they attain the same status as Zoroastrians and other non-People of the Book attained? And would it make any difference if the movement itself claims to be monotheistic or henotheistic rather than outright polytheistic?