If eg it's Trump vs Kamala and Kamala concedes, how does this resolve?

Good question. This will resolve NO if either the Republican or Democrat nominee concedes by Dec. 5. So if Kamala Harris is the Democrat nominee and concedes before Dec. 5, this will resolve NO.

Could you change the title to reflect that?

Good suggestion, given the turmoil of this election. Thank you.

Trump won't concede regardless of the result of the election.

Biden will only concede if he is the candidate and loses. He's likely to lose if he's the candidate, but hopefully he won't.