In a hypothetical scenario where Pakistan was balkanized, and an independent state in Sindh, Punjab, etc emerged, then one could say the Harappan genome gave rise to Sindhudeshis, Punjabis, etc. It doesn't mean anything.
To me, it just seems this is derives from pointless and meaningless competition with Indians for IVC. The only reason Indians kang and chimp on these things is because many of them are religious fanatics who genuinely think it's a point of pride that their society is still locked in stone age customs. Similarly, there are many of them are embarassed that their country is deeply backwards and regressive, and the only positive spin they can make out of it is bragging about "cultural continuity".