I was taking a look at the Level 4 Administrative Boundaries for Malta, and they seem to be matching a version that is no longer used (since 2021) Image here and I feel they should be updated to the current version that was implemented after this as seen here
A main source that I have for this data is the legislation passed by the Maltese Government in 2019 available here , and if you view page 35 of this document it contains a list of villages and towns that comprise the regions.
If this is the wrong topic to post this under please let me know.
Publicly available in this case may not necessarily mean in the public domain. Since OpenStreetMap is a very niche project, it probably doesn’t fit directly under any copyright exemptions. If you want to contact Legislation Malta about this you can take a look at these templates for some inspiration.
I agree that the region boundaries need to be updated, but it’s good practice to get explicit permission for use within OSM if the terms of use are unclear.