As per appstream spec, /usr/share/metainfo/ is a successor to the /usr/share/appdata/ directory and the preferred location for installing appdata files. More and more packages are getting changed upstream to use the new location. The filesystem package already owns the /usr/share/appdata/ directory. Please add /usr/share/metainfo/ as well so that individual packages wouldn't need to create it.
Ok, makes sense...
Forgot to close this one in March...
Thanks!