There has been no change to openldap from 7.8 -> 7.9. I've only just prepared the update and it is in updates-testing, so not released. It is also just a trivial patch upstream. The message you are seeing about "Configuration directory '/etc/openldap/slapd.d' does not exist." is normal. Since Centos7 is in maintenance mode we should not expect many (any?) major app changes from them. Slapd is covered by servicewatch so should try to start every 5 minutes if it is not running. If slapd does not start, it can stop winbind from starting (which is also covered by servicewatch). Perhaps look for issues in the boot log and/or messages log during boot.