That would be a fascinating political, social and economic phenomena. A distinct minority, ostensibly with a different religion and culture, suddenly finds itself “reunited” with their “brethren”. Suddenly thrust from being a minority with limited political rights in a First world country to being part of a third world majority. Careful what you wish for.
Quebec separatists don't want people in Quebec to know that separation means: no Canadian passports, no federal government jobs, no right to employment in other provinces, no automatic free trade with Canada, etc. etc. Upon these realizations, the desire to separate cools.
I once read something about the Palestinian Arabs that talked about an Arab village which was split in 1948 by the Green Line—part of the village was in Israel and the other part in the West Bank. Apparently they had little or no contact in the period 1948 to 1967 although many or all would have had relatives on the other side of the line. After 1967 they could interact but they discovered they had become different—the Israeli Arabs were different from their cousins who had lived under Jordanian rule.