It seems you do not know where is the home town of the current VNese president.
Quang Ngai, a SVNese province. Yes he was an ex VC.
Almost of info you have in your question is false.
4/8 presidents of VN after 1975 were and is SVNese people in which, 3 later ones were ex VC - Nguyen Minh Triet, Truong Tan Sang and Nguyen Xuan Phuc (current PR). The 1st one was the acting president of DRV since 1961 and PR of DRV right when Ho Chi Minh died in 1969. He still continued to keep his president post of VN after 1975, until his death in 1980, PR Ton Duc Thang.
5/11 primer ministers of VN after 1975 were SVNese people. 4 later ones were also ex VC - Vo Van Kiet, Phan Van Khai, Nguyen Tan Dung and Nguyen Xuan Phuc. The last one was elected to the current president of VN. The 1st one was all war time PM of DRV, since 1955. He continued to keep his post after 1975 until his retire in 1987. PM Pham Van Dong
The current VNese gov then is not just the successor of DRV, which was called NVN by the west but also of NLF, famous with the acronym VC.
All the leaders of DRV war effort were SVNese people - PR Ton Duc Thang above, PM Pham Van Dong above and General Secretary of VCP, Le Duan. His home district was Trieu Phong, just about 40km south of Ben Hai river, in SVNese soil.
If the current VNese gov was something succeeded of “only” DRV, it also was the succeeded of something SVNese.
Furthermore before the VN separation by the US, there would be a general election on the whole VNese soil in 1956, in which, the former POTUS Eisenhower with his thinktank estimated that 80% of VNese would support DRV ( Eisenhower's Views on the Popularity of Ho Chi Minh )
“ I have never talked or corresponded with a person knowledgeable in Indochinese affairs who did not agree that had elections been held as of the time of the fighting, possibly 80 per cent of the population would have voted for the Communist Ho Chi Minh as their leader ”
This number of 80% of VNese meant at least 60% of VNese people already supported DRV back then. With the reunification 1975, a lot of anti-communist ran in exile out of VN, the support for unification idea of DRV back then and current VN would not less but inceased.