No he has no threat in pakistan, he visits here after every 2 to 3 years because there is no one to tell the police that he has 2 identities.A few points:
1. Did your uncle move to Canada as a refugee due to religious persecution in Pakistan?
2. You may want to remove the personal information/names that you've posted in your previous post. It could seem like you are defaming him and he could file a defamation/libel suit against you.
3. Regardless of how he gained his residence status in Canada, IRCC would have run background and identity checks to confirm that his statements are true. If he had misrepresented factual information, he would have been banned for 2 years. Even if it is proven true now, his Canadian citizenship can be revoked.
4. Not sure why you think your uncle will move back to Pakistan after he has built his life using a fake identity. He is probably aware that by changing his caste/identity, his life could be in danger if he returns to Pakistan. Just a thought
But now that I have told the police here about his 2 identities he will face problems here by the police only, not from any cast or religious extremist because these things doesnt exist in big cities plus there was never a threat to his life here and never will be.
His wife told us how she acted in front of the person who was taking the interview and told him how few extremist was about to kill them and she told us that we took the chance ,we knew that if we get caught they will ban our entry.