I don't think thos means what it looks like. Of all the countries in the world, I'm certain of only two who deeply study China: Singapore and Vietnam. That quote speaks from a place of familiarity and fear. Even if Vietnam gets into a conflict with the US, the Americans will eventually go away and Vietnam will proceed as before. On the other hand, China is right there and a conflict with the has a chance of wiping Vietnam as a country. This has happened multiple times before so Vietnam always has to be wary.
As for the deal itself, Vietnam is desperate so it'll agree to anything. Back in April, it was the first country to try to surrender so there are no surprises here.