In Karachi Muhajir=Urdu Speakers+Gujrati Speaking Memons+Biharis+Bangalis(Who didnt went back to Bangladesh after Fall of Dhaka like Alamgir)+Kuchi(To certain Extent)No it does not. Cut the crap now.
My ancestors (grandparents from both sides) migrated to Pakistan from India, all of my extended family has migrated...a good deal of people I know have migrated ancestors. And I am NOT a mohajir.
6.5 million people came to Pakistan from INdia in 1947. No-one calls themselves a Mohajir.
It's only a poltical gimmick used by MQM to gain sympathy of some sorts...