I've spent some time in China, and there, the constitution provides that the Communist Party has a leading role in society and is thus superior to any law. It may choose to enact and conform behavior to legislation and regulations, but that would only be a policy decision that law would encourage correct behavior of the populace. I'm curious as to whether the current Vietnam party and government have made the leap to where the Communist Party is always and everywhere subject to the law because it is the law, or if the Party is still superior to the law.
Private property in land is specifically written in to Vietnamese basic law now. The party, being by its very nature despotic, can annul that if they so choose but every day that would be more disruptive than the day before and would put a crimp on what is becoming the "Vietnamese Miracle" and would work against the Vietnamese government's most immediate goal, which is to become a protectorate of America vis a vis China.