External Identity issue on VMAX

Hello All, 

We have a situation, i am hoping someone can help us with this.

We have 1 VMAX and 1 Powermax System. Our previous storage team did NDM between these 2 systems. Now for a lot of LUNS on Powermax, i see external identity (WWPN) of the LUN resembles the vmax. We came to know that this is common for the systems which are involved in NDM.

Now, we are going to decommission the VMAX system. I would like to know if we power off the VMAX whatever LUNS on PMAX which have identity as VMAX gets impacted or not.

I could unmap the LUNS on PMAX and reset the identity, but that will need downtime. I see this issue on thousands on LUNs and frankly we won't be able to get approval for downtime on all the servers. So, if someone came across this or have any kind of information, please let me know.

Please let me know if you have any questions. 

P.S we do not have support for this VMAX system, so couldnt get help from EMC support.