These are not the diplomatic events described by the article. Surrender events are dominated by military personnel and not diplomats from places other than the belligerent. In fact, there are separate diplomatic events related to each of your examples. The more relevant event for [3] took place at san francisco.

https://en.wikipedia.org/wiki/Treaty_of_San_Francisco

(You were probably biased by the appomatox court house surrender, which was an outlier in that article, which, presumably, the author had to include out of fervent provincialism)