As we all know that Pakistan was created as a state not just for the Muslims of present day areas and regions that make up Pakistan but rather for all the Muslims of the sub-continent. Therefore Pakistan should allow Indian Muslims to migrate to Pakistan permanently and take up Pakistani nationality who wants to do so. Its more imperative for Pakistan as Muslims because the illegitimate Israel being non-muslims and jews has kept its doors open for any jew wanting to migrate to Israel.They even have established a separate govt department which facilitates those wanting to migrate to Israel. Moreover India also willingly accept hindus from Pakistan who wants to migrate to India for any reason and give them Indian nationality. So Pakistan should also keep its doors open for Indian Muslims irrespective of whether there's demand to migrate to Pakistan or not as a matter of principle.