I don't want ANYBODY from before this game being involved, the difference between Malgus and Revan or the Exile or Kreia is that Malgus is kind of the Malak of this game, not the true big bad but the main antagonist/protagonist nonetheless.
I think what they(DK and BW) did to the characters of Revan, the Exile(Meetra Surik is a terrible name), HK-47, T3-M4 and others was a cop-out merely intended to make the people of the Old Republic 'better', but they have done the damage, retconning any of this stuff simply won't do any good and further ruining the mystery of the once great Revan character is the total opposite of what should be done.
I think they took a giant **** on HK,T3,Meetra and Revan too but the only difference is Revan is the only one that can be saved because He didn't FOR SURE die on the foundry he just got DEFEATED so his character can be saved if they did something epic like my idea. They cant save the other 3 because they KILLED them off, there's nothing that can be done. I understand what your saying about leaving characters in the past but Bioware DIDNT leave them in the past they brought them back.