In that scenario, systemctl is-enabled UNIT can be used. The exit status will give if the unit is enabled or not on the system and then, according to the exit status, you do the transition or not. You would have something like:
if systemctl is-enabled OLD_UNIT then
systemctl stop OLD_UNIT
systemctl disable OLD_UNIT
systemctl enable NEW_UNIT
systemctl start NEW_UNIT
endif
Repeat for each unit that needs a transition. Maybe put a for loop if wanted.
or just write message while install package 
Now the Files listing has been refreshed, too.
Everything is fine.
Lessons learned:
Do not trust what you see at first view
Gitlab is a great source of information
but in this case not very helpful.
Because I know my environment very well
in some cases I just want knowing reliably
the hows and whys things change
so I can decide to apply a patch immediately or wait (for example).
Thanks for your hints
Seems manjaro wiki is down with a case of the Vid, or something
Hi philm,
after stable-update-2020-11-18 I had a black screen after boot (Black screen after [Stable Update] 2020-11-18) although I had the latest sddm version. I kept upgrading and this update also did not solve the issue, but downgrading to sddm 0.18.1-3 solved it.
So I think perhaps there might be something that manjaro team can do, so I don’t have to stay on that version “forever”, or do I need to file another sddm bug report?
Perhaps you could add it to the Known issues and solutions section.
This seems to be different from the PAM and PAMBASE issue, since I don’t have a system-auth.pacnew
For help of others that may experience this its resolved. From sudo rename /home/(user)/.config/audacious folder to something else. Try starting Audacious from the desktop icon. Mine restarted. When you do this Audacious will create a new /.config/audacious folder. Playlists will be empty. In my case one of the things I wanted to save was my playlists. I deleted the Playlists folder in the newly created /config/audacious folder and moved the Playlists folder from the renamed audacious file from .config into the new folder. So far so good, seems to have functionality as before.
Regards & hope this will help someone else.
Hi, after the update I can login but I can’t reach my desktop. I’ve logged in through tty2 and i’ve restored my system with timeshift.
I don’t have any pacnew file in /etc/pam.d and the cups patchs didn’t resolve the problem.
Please tell me what should I do to get some help.
Thanks
Oh, I forgot to say that after login the system asks for a password to kwallet, but it gets stuck.
Have you tried creating a new user (E.G. indaleto2) and logging in there?
Does this have the same problem?
Hi, thanks for your replay.
Yes I’ve tried and even install xfce on it before the update but the result is the same.
That command enables the cups.service so it auto starts at boot, the --now part says to also start it right after the command is executed so you don’t need a reboot for it alone.
This is just evidence that some people are still not familiar enough with systemd, you can’t really blame them though because there are so many parts that one needs to get familiar with 
But when it comes to the right way of doing things, then i agree with what @Frog suggested…
Again it is just philosophy, and as Manjaro is Arch derivative, many packages will bring this philosophy. But this is not place to discus such thing.
Update on 12 Systems without Problems.
DK3
Yes that is true, not everyone use printers. Set up printers is sometimes tricky in Linux.
I do not blame Manjaro on this, I understood this is an Arch based distro.
I prefer Manjaro to Arch because I need a rolling distro , that is fast , reliable , but do not update in every hour.
I had issues with upgrading my system with pamac and since then I mainly use pacman to upgrade my system.
So this is pure Arch philosophy , nothing else. Not for average users, right ?
Not so user friendly, RTFM .
I was not aware of the output when updating cups :
[2020-11-28T14:39:01+0100] [ALPM-SCRIPTLET] >>> Cups systemd socket and service files have been
[2020-11-28T14:39:01+0100] [ALPM-SCRIPTLET] >>> renamed by upstream decision. Please make sure
[2020-11-28T14:39:01+0100] [ALPM-SCRIPTLET] >>> to disable/reenable the services to your need.
[2020-11-28T14:39:01+0100] [ALPM-SCRIPTLET] >>> hint: “pacman -Ql cups | grep systemd” and
[2020-11-28T14:39:01+0100] [ALPM-SCRIPTLET] >>> “ls -lR /etc/systemd/ | grep cups”
“Hint” 
Packaging is hard but some people are just lazy
Update at VMware guest with KDE went without issues.
FYI Mesa 20.2.3 still have KDE grafics bug.
So I had to stay with AUR’s mesa-llvm-rc 20.3-rc2.