This question <https://english.stackexchange.com/questions/111070/are-constructions-like-thats-me-out-then-primarily-british-rather-than-ameri> is more about "that's"

This question's answers <https://english.stackexchange.com/questions/189416/when-a-person-replies-with-a-sentence-starting-with-then-than-should-it-be> are very close, but the "then" is almost a conjunction there, not an offhand interjection

Related, the "yes", "right", "no", "ja", and "okay" in

 - The one around the corner, yes?
 - And we'll meet again on Tuesday, right?
 - We don't want to be too hasty, no?
 - We've covered this topic before, ja?
 - So we will only stay a little while, okay?

do not read like classic question-tags as they do not use a form of "to be". They might confirmatory  or leading

This is not in the form of a question, but it feels the same to me
 - We'll see you at the party, then

Even when the sentence has a question mark, sometimes it's not really asking (allofunctional implicature); I just want to know what that last word is called and if it should ever be "than"

Cheers