Homebrew XY files?

[1B51004]

I had recently ripped the ROMFs of my Pokemon Ultra Moon game. While I was TRYING to move the data over Google Drive (apparently there's a limit of how big the file size is that i didnt realize until today), I had noticed a lot of files with something like '...xy_dress...' or '...xy_battle...'. They're probably just music files or leftovers from X and Y, but I just want to make sure it's just that and not something related to the game.
Many thanks, 1B51