Unlikely, in my opinion, for 3 main reasons:
Ethnic militias are not that strong. Azeris don’t have any militia, and Balochs and Kurds are far from their prime. 20 years ago they could do a lot, especially with air support, but nowadays they don’t have the required numbers or the fighting experience.
Ethnic lines are not so clear cut. Marrying other ethnicities is not a taboo, and people do it all the time. It is becoming even more common because of military service, universities, urbanization, and remote or contract work. The Supreme Leader, President, and Parliament Speaker have mixed ethnicity parentage.
Religion is dying and nationalism is taking its place. it is visible everywhere.
Even if they are less religious, they have many incentives to hide it. it is a theocracy after all. There are some minor signs that they are becoming less religious: leaked photos of their children, and private events like weddings, are usually quite liberal.
Some of them have an apocalyptic mindset. they are not the majority but the previous supreme leader gave them a lot of power and recognition. there are some evidence that they are getting sidelined, but It is still too early to know the power dynamics and main objectives of the new leadership.