When going through mass disbaling mess there are very little options the admins can do. 

Here are is option #1 the admins can possibly take.

IF YOU KNOW WHO THE REPORTER MIGHT BE or PLANING ON STAYING IN FACEBOOK then I would suggest option #1. 

Either open a completely new different roleplay and ONE BY ONE get the members to APPLY on the aff thread. 

Or do a REVAMP of a COMEPLTE DIFFERNT ROLEPLAY. If you have an old thread then use it and pretend its a revamp and get all the members over. 

IF UNSURE OF WHO THE REPORTER IS

try to list up any possible drama that have happend in the roleplay or anyone that has been salty with what has been happening or towards someone in the roleplay. 

is it a mass disabling or the same people getting disbaled over and over?

if certain people are beign target, then few options could be changing face claims or staying low on activity publically (groups and walls) or dont annoucne their new accoutns for a week or two.

the reporter possibly could have already left the roleplay. but they could be tracking the memebrs down through another person's friendlist, picture's likes & comments (open or still friends). or by checking the group member list. 

even if a group is closed or secret if a person have been in that roleplay before then they cna go back to the group and check the list of members and access who is in the roleplay. 

you could either make new groups and move the current memebrs over SLOWLY or block people from the groups as you delete them.

PRECAUTIONS

Always make sure to have blocked the reporter's aff and facebook name.

NEVER get the memebrs to reuse the account they used for the previosu roleplay since this might expose to a chance of tracking. Get everyone to either make a new accoutn or recycle antoher one. 

Make new groups as well.

I have seen few roleplays that have done this and survived it.