The (Updated) portion of the keyword is crucial. Early 100% save files from 2011-2012 often excluded the Casino Night DLC or the StreetPass content. A true sonic generations 3ds 100 save file upd refers to a save that includes the 3.0 update data, ensuring that the DLC pinball table is 100% complete and that all StreetPass ghost data is unlocked.
For players looking to skip the grind in the 3DS version of Sonic Generations