Dataminers found files with internal names like STRM_BGM_GCN_WALUIGI_STADIUM_32K , which directly mapped to known series tracks.
Released alongside Wave 2, this update contained leftover data.
The leak was considered "mega" because it provided concrete evidence for tracks across multiple upcoming waves, specifically focusing on Wave 3 and beyond: London Loop (Tour) Peach Gardens (DS) Boo Lake (GBA) Rock Rock Mountain (3DS) Berlin Byways (Tour) Waluigi Stadium (GCN) Merry Mountain (Tour) Rainbow Road (3DS)