@ Jerry Lee
It's happened in VAC (Vietnam Airlines) Whether you are with RAL or Parc or DPI. The soonest upgrade I heard was a year on the right seat, to the left of the same type (A320, that is). Most if not all, at least two years as FO before you get a chance for upgrade on the same type from right to left. Less than that for upgrade to bigger planes (320 to 330 as FO). Longer period for upgrade to wide body when you'r on the left seat. The company is expanding, that might be your clue why it has upgraded expats that fast.