That is nice and all, but the exile isn't learning how to use the Force again, because he isn't actually using the Force. He has some Force-like abilities that he leeches from those around him and presumably from those he kills, through some weird Force bonds. So all of the losing an arm and suddenly getting it back analogies don't really apply.
But you are forgetting something even more important, Kreia herself had had her own connection to the Force somewhat severed, so her situation isn't any better than the exile's.
No, I didn't like Kreia lecturing me all over when supposedly the exile is a war veteran and an accomplished Jedi. I was really expecting a game in which the PC got to be the master, but this time around you're just another whelp.
The whole Kreia mentor business is just a plot device to give the Darth Traya plot a deeper involvement for the player. If you try to dissect it, it doesn't hold very well.