The Access Points will try to connect to the Zone Director based on the ZD IP address.
So if you restore the configuration backup and the new ZD has the same IP as the previous ZD then the AP's should join the ZD.
There are three options when restoring a config backup on a ZD
Restore AP, WLAN,
In your case you should restore everything making the new ZD a clone of the original, including all AP information already configured.
Make sure the new ZD is running exactly the same version as the version on the old ZD when configuration Backup was created.
You should not have to touch the Access Points, but they should be reachable via SSH/CLI for diagnostics if you run into issues.
For some more details on restoring configuration for AP's on ZD please check this Knowledge Base article:
AP configuration restore on ZD
Restore AP configuration alone on ZD from GUI
I hope this answers your question,
Thanks for choosing Ruckus Networks - a Commscope Company.