Does restoring a backup change the DNS cnames?

Hi, I have a new hosting customer, and their cpanel account needs to be migrated from their old host. I already generated a full back up of their account. The domain in their old account has some dns cnames that point to Amazon s3, as well as MX records that point to gmail. I noticed in the past, that when restoring an account, cpanel automatically replaces the ip addresses of the old server with the current server's ip addresses, throughout the dns records. Does it only replace existing ip addresses? With it also replace the cnames and mx records with the new sever's ip addresses, or with it leave them intact? Thank you