As for other information that might determine the truth, I found this documentation:
https://fam.state.gov/fam/07fam/07fam0270.html
There's a bunch here and I'm not fucking reading all of it but three points that stood out to me:
1. (as to QwahlityKahntent's wrinkle) non-civilian deaths are handled separately.
2. There is a specific form filed for non-natural civilian deaths abroad, the DS-2060. Copies of the DS-2060 can only be sent to the legal representative of the deceased, so it doesn't seem like that information can become public knowledge.
3. There's a specific carveout for situations in which the local death certificate isn't ready within six weeks, but a preliminary one is, in which case a preliminary DS-2060 is still filed. And if the local death certificate isn't ready in any form within six weeks, the Next-Of-Kin is contacted directly with an explanation.
Now, the Department website has the following phrasing: "
Deaths that are listed as“undetermined/unknown” have been reported to the Department of State as deaths from non-natural causes, but local authorities have not provided additional information." That sounds a lot like point 3 above. If the local authorities don't provide a finalized death certificate, but do say it was a non-natural cause, the death *is* listed. I would like to think that Japan can figure out if a suicide was a suicide or not inside of six weeks, especially if the dude fucking hanged himself.
Which (I think) means, that even if there was some kind of "backfill" preventing the Department from finalizing a DS-2060, the death would *still* be reported, but the cause of death would be listed as "undetermined/unknown". There's a whole bunch of weird edge cases here I don't care to interpret, one of which is, if the locality where the death occurred hasn't issued even a preliminary death report and doesn't anticipate doing so inside of six weeks, does the death still get listed, or not. Or perhaps the "backfill" is *not* related to the locality's finalizing a death certificate. In which case the implication is here that the State Department dropped the ball. But if they did I don't expect them to wait until six fucking months from now to update the listing. I'd expect them to finish the certification and add it to the list. It's not like they're only allowed to edit the website every six months.