As recent as the last two updates, OSU! now no longer loads all new incoming beatmap files en masse but instead "Checks for new files..." and then "Loads new files only..." selecting the first cursor highlighted map via whatever folder or desktop they're coming from. (CTRL + X number of maps and Opening with OSU.)
The problem seems to be fixed if OSU client is already open but not if the loaded maps open the client themselves.
The problem seems to be fixed if OSU client is already open but not if the loaded maps open the client themselves.