@ Jakbawer,
As I have heard there won't be any more screenings right now for A330. As I have heard, there are some new expat entries on A330, but they were screened 3 or more months ago, coming now.
In the moment they are doing a lot of training on vietnamese pilots changing to A330, so there might be no capacities for expat entries.
But on long sight I think they will need lots more pilots (expat as well), because there will be more aircrafts coming into the fleet.
So if you wish to join Vietnam Airlines, put your application and wait, I am sure, there will be demand, but if you are looking urgently, maybe VN won't be best decision right now.
Best wishes