When our domain controllers machines are shutdown, it isn't necessary to check the AAIP? We are looking to use replication as a method to move the DCs to another VMware host. We have used this method to move over 50+ plus machines so far.
We do checked AAIP when we run backup (server is online).
It is always recommended to enable AAIP when backing up/replicating live VMs, however in case they are shut down, this setting does not take effect (nothing to quiesce).