This is called reverse psychology...and my guess is it's India's way of sending a message to Pakistan to back off from the Khalistan movement currently brewing in Indian Punjab. Whoever backs this idea in Punjab will be committing political suicide and quite frankly be screwing Punjab further in case of Pakistan's case. Punjabis in Pakistan have no interest in creating a landlocked country.
A Khalistan however would be in favour of Pakistan, assuming the current Khalistan movement is only concerned about East Punjab, Jammu, Haryana and Himachal Predesh forming the borders of the new "Khalsa Raj". This would have two effects. One, we could deal directly with East Punjab (Khalistan) and secondly, it automatically cuts India off from Jammu & Kashmir.
In the case of Khalistan, having Pakistan as an ally would mean Khalistan would have access to our ports, which I assume would be denied by India. Hence Khalistan as an entity would be viable, only if East Punjab is the prize. If this turns into a "Pan Punjabi" movement, then bothsides will be losers.
India is attempting to turn the "Khalistan movement" into a "Pan Punjabi Movement" for this reason only.