I am not familiar with Mate and so I do not know whether something concerning these notifications is specific to Mate. I also do not know whether there are any undesired print status pop-ups on Mate's desktop.
I only know that after the system-config-printer fix any undesired pop-ups disappeared on standard Ubuntu Linux.
For the CUPS web interface as how by your screen shot I do not see the status messages as a problem. The show which printers are busy doing a job (did they actually do a job when you have taken the screenshot?). They are not marked as errors and they are not annoying pop-ups which interrupt the user's workflow.
If they are not there anymore in newer Mate/Ubuntu/CUPS versions then the upstream developers of CUPS have done changes.
Note that the changes in system-config-printer only eliminate annoying desktop pop-ups, they do not change anything in the web admin interface of CUPS. So recommend the system-config-printer upgrade only if the user is complaining about desktop pop-ups. Doing the update does not cause any known regression or side effect, so updating is no problem.
I am not familiar with Mate and so I do not know whether something concerning these notifications is specific to Mate. I also do not know whether there are any undesired print status pop-ups on Mate's desktop.
I only know that after the system- config- printer fix any undesired pop-ups disappeared on standard Ubuntu Linux.
For the CUPS web interface as how by your screen shot I do not see the status messages as a problem. The show which printers are busy doing a job (did they actually do a job when you have taken the screenshot?). They are not marked as errors and they are not annoying pop-ups which interrupt the user's workflow.
If they are not there anymore in newer Mate/Ubuntu/CUPS versions then the upstream developers of CUPS have done changes.
Note that the changes in system- config- printer only eliminate annoying desktop pop-ups, they do not change anything in the web admin interface of CUPS. So recommend the system- config- printer upgrade only if the user is complaining about desktop pop-ups. Doing the update does not cause any known regression or side effect, so updating is no problem.