Joining in on this conversation to say that I am experiencing the same thing and oddly, some 19 hours since I performed the upgrade, my system crawled down to an almost grinding halt. None of my shares were accessible and the web UI seemed to load the login page but could not get beyond that. Couldn't even ssh in to diagnose what was going on and no glaring clues in the syslog stream other than it stopped dead after some smbd activity.
Performed a soft shutdown via IPMI and it took approximately 30 minutes for all services to timeout and be forcibly killed before powering down. System back to normal after powering up but this journald notification is happening for me too.
That being said, I don't believe the two issues to be related, given that journalctl --disk-usage reveals only about 34MB (hah!) so those errors are most likely just noise, more than anything else. This is in 23.10.0.1.