If you have made any modifications to those files, your changes will be lost.
You should always update Word Press to the latest version.
You will only be able to update the information of the websites that you are listed as Site Owner or Site Administrator.
However, you can't use the method described in that article to solve this problem.
That method requires that you identify all JSF components and write them into your JSF pages.
What if the dynamic elements cannot be identified until run time?
At this time, JSF has no good solution to this problem.
If the fix was successful, the display will indicate that the database is up to date. In some cases, when you update to a new Joomla version, new core extensions are added.