a few of it anyways.
ALSO Explain to me, why would a DLC character be using audio files that were added during regular installation? It would make more sense for a DLC character to be using audio files that were downloaded during that character's DLC download process, no? Those files also seem to only be "idle chatter" type audio files, meaning the things she would say if she were on the Citadel, or Illium, or Tuchanka, or Omega, you know how there's the "Talk to Garrus" type thing that pops up in the hub worlds, those are what I'm talking about. It's not as if you've got audio files that would play when you meet her, talking about her story, and how she joins you etc...
Also, one big consideration that just came to my mind when listening to those... How do we know she'd really be a character that would join you? For all we know, she could simply be a character who is involved in a line of city missions that is involved in a future DLC. Example: It starts in the Citadel, Captain Bailey mentions to you that there has been a bit of a problem lately with a thief (Kasumi) who has been stealing things (he'll list a number of things), and Shepard takes it upon themselves to go find out who's responsible, within that, they end up finding Kasumi, who they end up having to chase, from the Citadel, say she goes to Illium, and the audio files that have been found, they can simply be a small thing like if you chat to her before that part of the mission is active, she'll give you some flavor chat. Anyways, you then go to Illium, chase her more, she escapes and makes her way to Omega. There's no necessity that Kasumi would join you at the end of this mission line, it could simply be a mission such as this... True that it could be considered a bit of a stretch saying all of this, however, it's no more of a stretch than people saying she's ABSOLUTELY a future DLC character that joins your squad.
Because the Voice actor(ess) in question may have had timing issues if it was done later do to other commitments.
And its rather routine to include functionality to be used later in the base game. Saves on download sizes and such.
That is just for starters.