Hi Stefano!
This does not mean with this new 20.0.1 release, but with MATE itself in Manjaro. It's about an extension for Caja file manager that I was not able to find: caja-admin, a python-written extension to have root privileges in the context-menu in Caja.
There it is "caja-gksu" in AUR, but is not the same as that I'm looking for.
The issue is that in fact the package I'm looking for is in Debian, with the name "caja-admin", so it would not be very difficult to convert that .deb to an arch-package.
Why nobody has done this before? Is due to dependencies? Is there something else?
These are the dependencies on Debian:

I could make the arch package and put it on AUR, but before I want to know if there's any problem.