FYI, when I upgraded to 5.0 the Printer module was removed from Zentyal. However CUPS remained installed and the printers still existed along with the config files. Only issue was that the include for printer.conf was removed from the samba config. You can add it back by editing the mas file (/usr/share/zentyal/stubs/samba/smb.conf.mas).
I don't remember if I had an issue or not because I had already altered the smb.conf.mas file before so that all printers were automatically shared.
Without the GUI you might find setting permissions a bit trickier. Those settings in the GUI were, I believe, for restricting access to who could add the printer through the samba share. You can do that manually through the samba config. Or restrict at the CUPS level. The CUPS web interface at
https://hostname:631 still exists.
Personally, I didn't want to rely on Zentyal to keep CUPS current or to potentially cause issues for me with printers so I spun up a separate Ubuntu server, added it to the domain, and installed CUPS.