And then if you figure since you're in the neighborhood, why not poll older folks in Vietnam? After a while, one might see where I'm going with this. And if you need a hint: on balance, I'm not convinced of the claim.
Polls of older people in Vietnam might reflect some survivor bias. The communists weren't very gentle to regime opponents.
Apparently they weren't gentle to ethnic Chinese either, I have met many that were forced to flee in boats to avoid pogroms.