What do you think it should be? We know she survives, when the exile goes to look for Revan, so what role should she play in KOTOR III?
Techincally, she may not have surivied for a Female LS Revan. It is strange that she did not appear for Female LS, but appear she did not.
The reason is the fact that it is harder to save Bastilla if you are Female, because Bastilla is not a leb/love interest like Jhunai is. Therefore, you have to play a very good mini-game to save Bastilla...which is hard. I guess that the makers of K2 was afraid that many players were unable to win this minigame and decide to leave Bastilla's fate in the lurch for someone who set Revan to Female LS...since she could possibly die.
Because of this, I suspect that Bastilla will not reapper in K3, at least not for Revan Female LS issue. If she does appear, then it will only be a cameo apperance, like that small talk you get if you set Revan to LS and meet up with Carth (and Bastilla if you are Male LS).
Hm, I wonder if we get to see Bastilla's corpse in the Unknown Regions for playeres who set DS Revan. After all, Bastilla did leave known Space to find Revan if you set Revan to DS, angry that the Sith are killing each other, and afraid for Revan and this threat to his power, what we know as the True Sith.