His personal story in KotOR involved saving his son from the academy on Korriban. If lightside Revan is canon then Dustil should still be alive. Plus I wouldn't mind if they modified canon a bit to see another Onasi. I'm also sad that they didn't have the Onasi blaster as a legendary item, or Bindo's robes.
'In Star Wars: Knights of the Old Republic II: The Sith Lords, Dustil was supposed to make an appearance in the tomb on Korriban. Dustil would claim that he is a Jedi and turned his back on the dark side only to return to Korriban for reasons unknown even to himself. While inside the tomb, Dustil would claim to have encountered and killed Carth twenty two times while other times, Carth had killed him. While speaking with the Jedi Exile (who he believes is just another vision) he would cry for his father and ask why he left him. Dustil would then become enraged and attack the Exile. However, the voice for the scene was never done, and was cut from the final version of the game. Instead there is a body labeled "Dead Jedi" in the chamber with a datapad belonging to a Jedi named Nebelish. The designers never changed the model for the corpse however, and he still clearly resembles Dustil.
I don't think they've ever decided on whether or not to make this C-canon, but it does make sense.