Ubuntu was planning to ship the CUPS printing stack as a Snap in 23.10 — but after several months of testing, its changed its mind.
Accordingly, a DEB-based printing stack will feature in Ubuntu 23.10 “Mantic Minotaur” and in Ubuntu 24.04 LTS. Switching to the CUPS Snap will now aim to take place during the Ubuntu 24.10 development cycle.
I don’t upgrade Ubuntu, just unmount home, tar the configs for reference and install the new one. I’ve lost more time in the past to hunting gremlins on an upgrade than doing a clean install and applying my configs.