Chinese economy already is outsourcing much to Vietnam, and Chinese culture is slowly getting more popular.Like most countries the same size, Vietnam lacks the internal market to really incubate national champions, so it needs a developed patron market. For Korea and Japan, that was the US. But the US doesn’t trust Vietnam since it’s not a vassal.
China could play this role for Vietnam maybe in 10-20 years. Only after it’s built up its own domestic champions already though.
Chinese anime dubbed in Vietnamese:
Chinese songs translated to Vietnamese:
Hopefully they'll be able to fix the current situation.