The GNOME people want everyone packaging software that includes icons and desktop files to call dh_icons and dh_desktop to accomodate their particular caching system. See #432851, #439717, and my attempt at discussion at #460504. I personally think they are approaching this matter in the wrong way. But in order to arrive at a complete solution for this we would somehow need a comment from the KDE packaging team. For one thing, a solution would require that the KDE core packages add those calls as well. What do you think?