There was a unified Indochinese Communist Party during WWII. Ho disbanded it in favour of pursuing a Vietnamese nation. I don't recall his exact reasoning for doing so.
Some things to consider though vis-a-vis Yugoslavia:
-the Vietnamese would be the majority (and in power), unlike the Serbs who were merely a plurality (and a somewhat suppressed one at that)
-The Vietnamese are much more geographically concentrated than the Serbs
-Yugoslavia existed before WWII and had formed via the consent of its constituents, Indochina had merely been a useful grouping of colonies and the only way that would change is if the Vietnamese dominated ICP conquers it all
As a result you have a demographic and political balance that favours centralization, but a demographic distribution which favours substantial decentralization and a population which is liable to see the project as a Vietnamese Empire regardless.