Coops is a potential wallaby in the making according to rugby journos. That is how far he has come.
Be careful taking the opinon of rugby journos, they're no better than their league counterparts.
Being considered as a wallaby is more a reflection of the state of union wingers than Vuna's form. Most of Australia's top flight wingers have had season ending injuries or issues with suspensions or moved to completely new positions to suit their club.
Vuna has been ruthlessly exposed defensively. He has improved this year but is still a very weak link in his teams backline. The fact he still gets picked is because he is just as dangerous a ball runner as he was with the Knights.
He's definitely a league player, not a union player. NRL just suits his skillset better. I'm certain he himself knows that. However, he may not be prepared to give up on his union experiment yet.