The community repo is only one example where a .pacnew file has been created but left unattended for a very long time. That the community repo hasn’t been attended to is a strong indicator that other (more important .pacnew instances) have also been neglected.
Content of a .pacnew file may need to be merged (or even replace) the content of its associated file. However each should be viewed first to determine how each instance should be handled.
There is often information in a respective Update announcement when a .pacnew needs attending to, as was the case with the community repo change over a year ago.
- From the Update 2023-05-21 announcement.
Here is the explanation of Pacnew and Pacsave files in the Arch Wiki:
The link already given (from the Manjaro Wiki) is usually sufficient as a starting point, though I recall seeing many discussions on the general topic within the forum:
After researching the topic, if you still feel it’s largely above your head, you could create a new thread and ask for input. This may attract some more detailed information from other Members, and cultivate a better understanding.
Perhaps there are a few guides others are aware of. I know the topic has received much attention from many hoping to avoid dealing with pacnews at all. I’d guess most have been disappointed on that note.
Regards.