Harrold Andraste said:

Kreia helps the Exile reestablish their connection to the Force and led her to fight Sion and Nihilus. So what? Vrook, Handle Bar Mustache, and the Iziz Jedi could train her, too.

But that's not the way it happened. What ended up happening was that Kreia help The Exile reestablish her connection with The Force. We're not talking about what ifs and what could have beens here. Also part of the reason they exiled Meetra was for the same reason Kreia took interest in her. Because The Exile was a wound in The Force. Not only that they saw The Exile as a rebel and they blamed him/her for Revan's fall. It's a bit of a stretch to say the Masters would have trained her.

Also if it were't for Kreia The Exile would have died on the ship the game started out on.