Pretty rare to see two linked Wikipedia articles contradict each other that much.
It isn't contradictory. The french did colonize vietnam and force cash crops on vietnam ( like all colonial empires did ). But during the indochina war ( 1st and 2nd ), vietnam's coffee industry ( and all non-war related industry ) crashed due to the war itself and sanctions levied by the US/France. Vietnam was pretty much barred from trading with the western world, their primary market.
As the indochina war drew to a close and the coffee industry revived because of friendly soviet-vietnam relations and the opening of markets in soviet dominated europe. It wasn't just coffee, lots of vietnamese immigrated to soviet dominated to work and study as well. At one point, the largest non-white communities in eastern germany, poland, etc were vietnamese.
I remember an article in the WSJ by a Pakistani man ~2006, saying "the entire history of my country is a footnote in the history of US foreign policy", and it always stuck with me how much some events can have wide reaching and odd effects, disproportionately felt by specific groups.
They bought coffee on the international market but didn't have enough money to buy enough. Raising prices in local supermarkets wouldn't have helped much because internationally their currency was close to worthless.
Article describes how some probale unfavourable weather pattern derives in coffee issues in Brazil, then is producing effects ( including political!) in East Germany then in Vietnam. Which said effects might even now influence the present.