Documents are accepted but NVC messaged the following

[Theersink 48]

17 hours ago, adivish said:

@Theersink Thank you for the heads up! We're actually planning on moving by next June. So we thought if we submit our docs now, our interview would get scheduled sometime in Feb and then we'd still have up to 6 months from then to move. The sponsor is a teacher so the school year ends sometime at the end of May/early June so we'd be moving about 3-4 months after our interview which we'd inform the consular officer about of course. Do you think that timeline sounds feasible?

I would say that is feasible but again I would not wait until the last few weeks of the visa expiration.  Expiration also depends on medical expiration. I'm not sure how long the medical is good for for VIetnam but if medical expires so does the visa. Just be vigilant and prepared to move your timeline if something comes up.