We strongly advise against upgrading your workstations to OS 10.9 Mavericks.
Esko Suite 12 will support Mac OS 10.9 Mavericks from Assembly 5 onwards. Suite 12 Assembly 5 is scheduled to be released in January 2014.
A note on ArtPro - OS 10.9 Mavericks compatibility
ArtPro 12.1.1 works with OS 10.9 Mavericks if the updated license managers are installed.
To update: