It would be interesting to look into the history of the demand for Khalistan.
Even when India was getting partitioned in 1947, Akali dal leaders (prominent among them being Kartar Singh, and Baldev Singh) had demanded Khalistan, at the time of India’s partition. Their theory was: if India remains undivided, Sikhs are fine living in undivided India. But if India gets divided, then Sikhs would also want a land of their own, namely Khalistan/Sikhistan.
Baldev Singh and other Sikh leaders, with Stafford Cripps (source Google)
This demand for a separate homeland for Sikhs was impossible to meet however. In undivided India, the demographics of Punjab (which included the Punjab part of Pakistan as well) were: 16 million Muslims, 8 million Hindus, and 4 million Sikhs. Further, there was not even a single district of Punjab, which had Sikh majority.
Hence, Khalistan was out of question. As for the fate of Punjab, an option at the time of partition was to leave Punjab intact and give it in entirely to India or Pakistan. Pakistan had a stronger claim, since Muslims were the biggest component of Punjab’s population. However, this was completely unacceptable to Sikhs, who were reluctant to enter the Islamic nation. Consequently, Punjab was partitioned and most Sikhs migrated to India, from the Pakistan side.
We have come a long way from that point now. India is now a sovereign nation, whose constitution does not allow any portion to secede. Hence, there would be no further partitions of India, going forward.