It won't update automatically, it'll only install the tickets that are available at the time you run it. But it would be quick to run it again - you could either leave it installed (maybe in a far off folder in the corner) and run it later when you know there has been a new game added that you want, or, when you want to run it again get the 3dsx file and make a 3ds folder to put it in, and put boot.firm from Luma 8.1 on your SD card, then you can use Rosalina to get into homebrew and run it. Then delete the files again afterward.