Comment 3 for bug 1793395

Quoting Thunar's FAQ:
"If you are a packager or a system administrator and want to provide a system wide default for the keyboard shortcuts, that is different from the default shortcuts in Thunar, you can create a file Thunar/accels.scm in one of the $XDG_CONFIG_DIRS. For example, if /etc/xdg is part of $XDG_CONFIG_DIRS (the default for most Linux distributions), you can install system wide defaults to /etc/xdg/Thunar/accels.scm. Thunar will then load shortcuts from this file on first startup."
https://docs.xfce.org/xfce/thunar/faq#where_does_thunar_store_the_keyboard_shortcuts

I already do achieve this by modifying ~/.config/Thunar/accels.scm on my machines. That's why I assumed that this is the right place to ask.