It still didn’t work… But later i first copied the data from the original sd card to my 32g-micro, and then copied the file names of the other micro (that one that new 3dsxl includes with itself) to my own micro. Then the miracle happens and the save data are back in the data management (I think it’s called “Extra data”) but the games are not showing.
To test it, I inserted Person Q whose map data was kept in the sd card and the maps are back. Does this mean, if I re-download the digital games, the save data will be automatically applied to them? … Thanks!