What is now Israel also once had a majority Muslim population.
The Sikhs in India are happy living peacefully in all of India and having an influence on the nation far exceeding their population. If you don't know, the percentage of Sikh population in India is less than that of Canada and Sikhs have had far more influence in India than Canada.
If Pakistan is so keen on Khalistan, they should return the historical homelands of the Sikhs in Lahore , Gujranwala, Multan and Peshawar to them. Then, India can think about the status of Amritsar.