Agpa cancellation does it effect already registrations

Hi Sirs, X has done AGPA  with possession to 3 members A, B, C.... A, B, C has executed sale deed for 4 plots... Later B died, due to death AGPA is expected to be revoked automatically...Then can X cancel only power of attorney in the AGPA  and make fresh GPA on A, B's wife, C to do registartion of remaining plots.. Incase of fresh GPA would the first 4 plots registration still valid or would it be cancelled