Its a bit off-topic, but someone might find it useful.

Deploying additional ldap adressbooks is (as far as i know) not possible via GPO, juts with reg-keys and you have to know the profile-name.
So I found a useful tool, wich deploys any ldap to default profile.
https://blogs.msdn.microsoft.com/emeamsgdev/2016/06/09/mapi-utility-to-add-ldap-address-books-to-existing-outlook-profiles/

LdapABManager.exe -m create -f "ABConfiguration.xml"