The challenge is to have the ATL Kurds remain largely an ethnoreligous group along similar lines to the OTL Yezidi, Druze and Copts.
Options can range from practicing a form of Zoroastrianism, Manicheanism or Christianity and Islam to a possible variation of Yazdânism (including Yazidism), depending on whether one believes the latter to be the pre-Islamic native religion of the Kurds or either an Islamic sect or Islamized syncretic belief system.
https://en.wikipedia.org/wiki/Yazdânism
Options can range from practicing a form of Zoroastrianism, Manicheanism or Christianity and Islam to a possible variation of Yazdânism (including Yazidism), depending on whether one believes the latter to be the pre-Islamic native religion of the Kurds or either an Islamic sect or Islamized syncretic belief system.
https://en.wikipedia.org/wiki/Yazdânism