Buying a House in Society: Old Possession Letter Matters?

Hi Gurus/Experts,

One of my acquaintances purchased a house in a society in Islamabad. All the documents were shared by Seller and allotment letter also. However, he has one confusion that Possession Letter was on the name of the first person who actually purchased the plot long ago.
Is it a matter of any concern? Does he need to get an updated possession letter as well or only transfer letter on his name will be sufficient?
@Its_ImtiaX_88 and other experts, kindly advise. Thanks

@yousafnoor , @isloo1 your comment also welcomed.