Loc I'm not entirely convinced about F/O 330 making more than Cpt 320 but again nothing is impossible. Methinks, it's of no importance whatsoever, which aircraft will the one get the upgrade on. A320 renders you to be more often confronted with operational decision making necessity so much needed at the initial stage. In fact that's recommended procedure from Airbus. That'd be appropriate if the airline would only hire on the right, NO DEC.
Practically seen, from FO or SFO point of view, he only relevant question is HOW LONG? The answer is not less than 4 years if at all. If 330 isn't an option even longer. Conclusion anywhere at any point anyone gets a chance to move straight to the left, kiss QR good by. People would maybe prepared to wait provided their welfare is taken care of and their families are happy. It's just competition.
Latest rumour aired is about a pay rise apparently approved by the government, wouldn't hold my breath for it. As with 330 upgrades let's wait and see.
Don't take it personally take it on the rocks!!!