Currently I noted the many users still uses 5.13-family kernel which is EoL for sometime ago.
Some of them just uses as was after installation.
Please consider to change default notification settings of MSM to notify about all events:
If I remember correctly, the suggested settings is differ from the defaults.
Thanks!
Just to verify, this is on KDE regular ISO ?
I remember we used to have bad verbage on the notifications - so users thought they Must install new kernel whenever one was released, even if it was a non-recommended kernel and user was running a supported LTS, etc.
… did that get ‘fixed’ by unselecting the notification by default?
Yes, KDE.
BTW, does MSM has different default options on different DEs?
Oh, that’s how it could be. OK. Probably my idea is not for everybody. Hm, or it is just description-related lack which makes users to understand some notification texts incorrectly.
But OK, it is just my raw suggestion, may be too raw.
unselecting the notification by default
How unselecting as action could be in a row with default. default - it is what I got from somewhere, action - is doing of changing. Now combining: unselecting by default. 
On that “line” my interpreter got a “BSOD” here 
and was restarted (I am not an English-native speaker).
As I understand the text labels of MSM settings, the settings selection on the screenshot in initial post are the most informative setting selection of all possible: notifications will be in whole bunch of event: not limiting by the only cases, so all cases (all only unchecked).
Last use case that simple kernel update from EoL to supported one fixes an issue: 4K,60hz的刷新率，经常掉帧
Current possible: Keyboard does not work on login