Partly, but Communism isn’t the sole factor.
Thinking about it, the only traditional culture that Communism destroyed was the culture of the elite and the imperial, since they favored the lower classes to rule. This either meant the elites and imperialties were killed or all escaped overseas, leaving mainland Vietnam without any high culture. So the beauty and grandeur that high culture showcases was gone once Communism won.
However, the Communist government, after opening doors, does try to restore the imperial palaces and preserve traditional arts, whether of low or high culture. So it’s not like they completely ban it, since there is effort in rebuilding.
Young people these days are also trying to revive ancient high culture that is gone in Vietnam, from the clothing to the arts. And the government neither rejects it nor welcomes it, so it’s in the process of rise.
But Communism wasn’t the sole factor here. Colonialism is also a factor, as the French were partly responsible for the loss of traditional writing system, fashion, and the arts. The arts, not as much, since French colonial time was a period of artistic flourish in Vietnam, but only French-influenced ones.
And then there’s Westernization. The freshness of the West makes most people abandon the tradition. Music, fashion, language, cuisine are all affected.
So Communism was indeed a factor, but it doesn’t deserve to be the only one to blame here.