Why is Soulcalibur(the first one) labeled as a mobile game?

[BlastoiseTheVGRipper]

...eventually released on Mobile and Xbox 360, they were basically just ports.

You kinda answered your own question right there, the reason they're listed under the "Mobile" category instead is because those sound effects were ripped specifically from the Mobile version of the game according to the submitter. Since there could be potential differences between the versions, if the original Arcade or Dreamcast versions were to be ripped later, then new sections could be made for their respective consoles.

There aren't any differences. That's the thing.

There could be differences in the sound quality.